step03_pandas.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "<p><span style=\"color:red; font-size:30px; font-weight:bold;\">pandas</span></p>"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "데이터를 분석할 때 가장 많이 쓰이는 라이브러리다.  \n",
    "• 아나콘다를 설치하면 Pandas가 자동으로 포함되어 설치 한다  \n",
    "• 행과 열을 쉽게 처리할 수 있는 함수를 제공하는 도구이다.  \n",
    "※ 각 열은 단일 데이터 형식만 저장  \n",
    "• Numpy 보다 유연하게 수치 연산 가능하다.  "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Series\n",
    "\n",
    "- index와 values로 이루어진 1차원 배열이다.\n",
    "- 모든 유형의 데이터를 보유할 수 있다.\n",
    "- 인덱스를 지정해 줄 수 있다. (인덱스 길이는 데이터의 길이와 같아야 한다.)\n",
    "- 명시적 인덱스와 암묵적 인덱스를 가진다.\n",
    "- loc : (명시적) 인덱스값을 기반으로 행 데이터를 읽는다.\n",
    "- iloc : (암묵적) 정수 인덱스을 기반으로 행 데이터를 읽는다."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import pandas as pd\n",
    "import numpy as np"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0    1\n",
       "1    3\n",
       "2    5\n",
       "3    7\n",
       "dtype: int64"
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "obj=pd.Series([1, 3, 5, 7])\n",
    "obj"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([1, 3, 5, 7], dtype=int64)"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "obj.values"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "RangeIndex(start=0, stop=4, step=1)"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "obj.index"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "a    1\n",
       "b    3\n",
       "c   -4\n",
       "d    0\n",
       "dtype: int64"
      ]
     },
     "execution_count": 5,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "obj2=pd.Series([1,3,-4,0], index=['a','b','c','d'])\n",
    "obj2"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "1"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "obj2['a']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "a    1\n",
       "b    3\n",
       "dtype: int64"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "obj2[['a', 'b']]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {
    "scrolled": true
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "a     0\n",
       "b    10\n",
       "c    20\n",
       "d    30\n",
       "e    40\n",
       "dtype: int32"
      ]
     },
     "execution_count": 8,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a=pd.Series(np.arange(0,50,10), index=['a','b','c','d','e'])\n",
    "a"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 9,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "10"
      ]
     },
     "execution_count": 9,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# 명시적인 index\n",
    "\n",
    "a.loc['b']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 10,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "10"
      ]
     },
     "execution_count": 10,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "# 순차적인 index\n",
    "\n",
    "a.iloc[1]  "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 11,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "a     0\n",
       "b    10\n",
       "c    20\n",
       "d    30\n",
       "e    40\n",
       "dtype: int32"
      ]
     },
     "execution_count": 11,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 산술 연산"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "a    10\n",
      "b    20\n",
      "c    30\n",
      "d    40\n",
      "e    50\n",
      "dtype: int32\n",
      "a   -10\n",
      "b     0\n",
      "c    10\n",
      "d    20\n",
      "e    30\n",
      "dtype: int32\n",
      "a      0\n",
      "b    100\n",
      "c    200\n",
      "d    300\n",
      "e    400\n",
      "dtype: int32\n",
      "a       0\n",
      "b     100\n",
      "c     400\n",
      "d     900\n",
      "e    1600\n",
      "dtype: int32\n",
      "a    0.0\n",
      "b    2.0\n",
      "c    4.0\n",
      "d    6.0\n",
      "e    8.0\n",
      "dtype: float64\n",
      "a    0\n",
      "b    2\n",
      "c    4\n",
      "d    6\n",
      "e    8\n",
      "dtype: int32\n",
      "a    0\n",
      "b    1\n",
      "c    2\n",
      "d    0\n",
      "e    1\n",
      "dtype: int32\n"
     ]
    }
   ],
   "source": [
    "print(a + 10)\n",
    "print(a - 10)\n",
    "print(a * 10)\n",
    "print(a ** 2)\n",
    "print(a / 5)\n",
    "print(a // 5)\n",
    "print(a % 3)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "a    False\n",
      "b    False\n",
      "c     True\n",
      "d    False\n",
      "e     True\n",
      "dtype: bool\n"
     ]
    }
   ],
   "source": [
    "print(a > [50, 30, 10, 40, 20])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "d    30\n",
       "e    40\n",
       "dtype: int32"
      ]
     },
     "execution_count": 14,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a[a > 29]"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 집계함수\n",
    "\n",
    "- add : 더하기 함수 \n",
    "- sub : 빼기 함수 \n",
    "- mul : 곱하기 함수 \n",
    "- div : 나누기 함수 \n",
    "- mod : 나머지 구하는 함수 \n",
    "- min : 최소값 구하는 함수 \n",
    "- max : 최대값 구하는 함수 \n",
    "- mean : 평균 구하는 함수 \n",
    "- median : 중앙값 구하는 함수 \n",
    "- std : 표준편차 구하는 함수 \n",
    "- var : 분산 구하는 함수"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 15,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "a    10\n",
       "b    20\n",
       "c    30\n",
       "d    40\n",
       "e    50\n",
       "dtype: int32"
      ]
     },
     "execution_count": 15,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a.add(10)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 16,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "a   -10\n",
       "b     0\n",
       "c    10\n",
       "d    20\n",
       "e    30\n",
       "dtype: int32"
      ]
     },
     "execution_count": 16,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a.sub(10)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 17,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "a      0\n",
       "b    100\n",
       "c    200\n",
       "d    300\n",
       "e    400\n",
       "dtype: int32"
      ]
     },
     "execution_count": 17,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a.mul(10)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "a    0.0\n",
       "b    1.0\n",
       "c    2.0\n",
       "d    3.0\n",
       "e    4.0\n",
       "dtype: float64"
      ]
     },
     "execution_count": 18,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a.div(10)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 19,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "a    0\n",
       "b    2\n",
       "c    0\n",
       "d    2\n",
       "e    0\n",
       "dtype: int32"
      ]
     },
     "execution_count": 19,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a.mod(4)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "0\n",
      "40\n",
      "20.0\n",
      "20.0\n",
      "15.811388300841896\n",
      "250.0\n"
     ]
    }
   ],
   "source": [
    "print(a.min())    # 최소값\n",
    "print(a.max())    # 최대값\n",
    "print(a.mean())   # 평균값\n",
    "print(a.median()) # 중간값\n",
    "print(a.std())    # 표준편차\n",
    "print(a.var())    # 분산"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## DataFrame\n",
    "\n",
    "- 가장 기본적인 데이터 구조이다.\n",
    "- 행과 열로 구성된 2차원 데이터 구조(Data Structure)  \n",
    "➢ 2차원 배열에 행과 열에 인덱스를 붙인 것이다.\n",
    "- RDB의 테이블 또는 엑셀(스프레드 시트)와 유사"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "array([[60, 71, 59],\n",
       "       [99, 69, 69],\n",
       "       [59, 50, 86],\n",
       "       [74, 82, 70]])"
      ]
     },
     "execution_count": 21,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "rawData = np.random.randint(50,100, size=(4,3))\n",
    "rawData"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 22,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60</td>\n",
       "      <td>71</td>\n",
       "      <td>59</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99</td>\n",
       "      <td>69</td>\n",
       "      <td>69</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59</td>\n",
       "      <td>50</td>\n",
       "      <td>86</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74</td>\n",
       "      <td>82</td>\n",
       "      <td>70</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     국   영   수\n",
       "1반  60  71  59\n",
       "2반  99  69  69\n",
       "1반  59  50  86\n",
       "2반  74  82  70"
      ]
     },
     "execution_count": 22,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df=pd.DataFrame(rawData,index=['1반','2반','1반','2반'], \n",
    "                        columns=['국','영','수'])\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 23,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1반    60\n",
      "2반    99\n",
      "1반    59\n",
      "2반    74\n",
      "Name: 국, dtype: int32\n",
      "1반    60\n",
      "1반    59\n",
      "Name: 국, dtype: int32\n"
     ]
    }
   ],
   "source": [
    "#df[0]   --> error\n",
    "print(df['국'])\n",
    "print(df['국']['1반'])"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 24,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "      <th>평균</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60</td>\n",
       "      <td>71</td>\n",
       "      <td>59</td>\n",
       "      <td>63.33</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99</td>\n",
       "      <td>69</td>\n",
       "      <td>69</td>\n",
       "      <td>79.00</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59</td>\n",
       "      <td>50</td>\n",
       "      <td>86</td>\n",
       "      <td>65.00</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74</td>\n",
       "      <td>82</td>\n",
       "      <td>70</td>\n",
       "      <td>75.33</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     국   영   수     평균\n",
       "1반  60  71  59  63.33\n",
       "2반  99  69  69  79.00\n",
       "1반  59  50  86  65.00\n",
       "2반  74  82  70  75.33"
      ]
     },
     "execution_count": 24,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df['평균']=round((df['국'] + df['영'] + df['수'])/3,2)\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 25,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "      <th>평균</th>\n",
       "      <th>na</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60</td>\n",
       "      <td>71</td>\n",
       "      <td>59</td>\n",
       "      <td>63.33</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99</td>\n",
       "      <td>69</td>\n",
       "      <td>69</td>\n",
       "      <td>79.00</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59</td>\n",
       "      <td>50</td>\n",
       "      <td>86</td>\n",
       "      <td>65.00</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74</td>\n",
       "      <td>82</td>\n",
       "      <td>70</td>\n",
       "      <td>75.33</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     국   영   수     평균  na\n",
       "1반  60  71  59  63.33 NaN\n",
       "2반  99  69  69  79.00 NaN\n",
       "1반  59  50  86  65.00 NaN\n",
       "2반  74  82  70  75.33 NaN"
      ]
     },
     "execution_count": 25,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df['na']=np.nan\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
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       "\n",
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       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "      <th>평균</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60</td>\n",
       "      <td>71</td>\n",
       "      <td>59</td>\n",
       "      <td>63.33</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99</td>\n",
       "      <td>69</td>\n",
       "      <td>69</td>\n",
       "      <td>79.00</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59</td>\n",
       "      <td>50</td>\n",
       "      <td>86</td>\n",
       "      <td>65.00</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74</td>\n",
       "      <td>82</td>\n",
       "      <td>70</td>\n",
       "      <td>75.33</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     국   영   수     평균\n",
       "1반  60  71  59  63.33\n",
       "2반  99  69  69  79.00\n",
       "1반  59  50  86  65.00\n",
       "2반  74  82  70  75.33"
      ]
     },
     "execution_count": 26,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "del df['na']\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
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       "\n",
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       "\n",
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       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "      <th>평균</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99</td>\n",
       "      <td>69</td>\n",
       "      <td>69</td>\n",
       "      <td>79.00</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74</td>\n",
       "      <td>82</td>\n",
       "      <td>70</td>\n",
       "      <td>75.33</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     국   영   수     평균\n",
       "2반  99  69  69  79.00\n",
       "2반  74  82  70  75.33"
      ]
     },
     "execution_count": 27,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df[df.평균 > 75]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
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       "\n",
       "    .dataframe tbody tr th {\n",
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       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60</td>\n",
       "      <td>71</td>\n",
       "      <td>59</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99</td>\n",
       "      <td>69</td>\n",
       "      <td>69</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59</td>\n",
       "      <td>50</td>\n",
       "      <td>86</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74</td>\n",
       "      <td>82</td>\n",
       "      <td>70</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     국   영   수\n",
       "1반  60  71  59\n",
       "2반  99  69  69\n",
       "1반  59  50  86\n",
       "2반  74  82  70"
      ]
     },
     "execution_count": 28,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df=df.drop(['평균'], axis='columns')\n",
    "df"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 결측값 처리\n",
    "\n",
    "1. NaN\n",
    "    - 자료형이 Float형이다.\n",
    "    - 배열에서 연산할 경우 오류가 발생하지 않지만 결과값이 NaN이 된다.\n",
    "2. None\n",
    "    - 자료형이 None이다.\n",
    "    - 배열 연산을 할 경우 오류가 발생한다.\n",
    "3. 처리방법\n",
    "    - isnull() : 결측값 확인 ( 결측 이면 True , 결측이 아니면 False )\n",
    "    - notnull() : 결측값 확인 ( 결측 이면 False , 결측이 아니면 True )\n",
    "    - dropna() : 결측값 삭제 ( inplace = True : drop후 원본에 반영 )\n",
    "    - fillna(Num) : 결측값을 Num으로 채워 넣는다."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "\n",
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       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>86.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       국     영     수\n",
       "1반  60.0  71.0  59.0\n",
       "2반  99.0  69.0  69.0\n",
       "1반  59.0  50.0  86.0\n",
       "2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 29,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df=df.astype('float64')\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       국     영     수\n",
       "1반  60.0  71.0  59.0\n",
       "2반  99.0  69.0  69.0\n",
       "1반  59.0  50.0   NaN\n",
       "2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 30,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df['수'][2]=np.nan\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 63,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "           언어            수리\n",
      "            국      영      수\n",
      "1학년 1반  False  False  False\n",
      "    2반  False  False  False\n",
      "2학년 1반  False  False   True\n",
      "    2반  False  False  False\n",
      "          언어           수리\n",
      "           국     영      수\n",
      "1학년 1반  True  True   True\n",
      "    2반  True  True   True\n",
      "2학년 1반  True  True  False\n",
      "    2반  True  True   True\n",
      "언어  국    0\n",
      "    영    0\n",
      "수리  수    1\n",
      "dtype: int64\n"
     ]
    }
   ],
   "source": [
    "print(df.isnull())\n",
    "print(df.notnull())\n",
    "print(df.isnull().sum())    # 결측치가 몇개인지 확인"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "\n",
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       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       국     영     수\n",
       "1반  60.0  71.0  59.0\n",
       "2반  99.0  69.0  69.0\n",
       "2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 31,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.dropna(axis=0)  #원본을 수정하지 않는다\n",
    "#df.dropna(axis=0, inplace=True) # inplace는 원본을 수정한다"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 32,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "\n",
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       "        vertical-align: top;\n",
       "    }\n",
       "\n",
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       "        text-align: right;\n",
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       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>hello</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       국     영      수\n",
       "1반  60.0  71.0     59\n",
       "2반  99.0  69.0     69\n",
       "1반  59.0  50.0  hello\n",
       "2반  74.0  82.0     70"
      ]
     },
     "execution_count": 32,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.fillna('hello')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
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       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
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       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>-1.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       국     영     수\n",
       "1반  60.0  71.0  59.0\n",
       "2반  99.0  69.0  69.0\n",
       "1반  59.0  50.0  -1.0\n",
       "2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 33,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.fillna(-1)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 34,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       국     영     수\n",
       "1반  60.0  71.0  59.0\n",
       "2반  99.0  69.0  69.0\n",
       "1반  59.0  50.0   0.0\n",
       "2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 34,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.fillna(0)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 35,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>66.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       국     영     수\n",
       "1반  60.0  71.0  59.0\n",
       "2반  99.0  69.0  69.0\n",
       "1반  59.0  50.0  66.0\n",
       "2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 35,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.fillna(df.mean())"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## MultiIndex : 다중 인덱싱\n",
    "\n",
    "- .T : 행과 열을 바꿈\n",
    "- .index() : 인덱스(행)를 추가\n",
    "- .columns() : 컬럼(열)를 추가\n",
    "- [ \\] : 컬럼(열)으로 참조\n",
    "- .loc[ ] 또는 .iloc[ ] : 인덱스(행)로 참조\n",
    "\n",
    "- 멀티 인덱스, 멀티 칼럼일 경우 : 각각 .loc[ ].loc[ ] or .iloc[ ].iloc[ ] 와 [ ][ ] 으로 참조"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 36,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       국     영     수\n",
       "1반  60.0  71.0  59.0\n",
       "2반  99.0  69.0  69.0\n",
       "1반  59.0  50.0   NaN\n",
       "2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 36,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 37,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>1반</th>\n",
       "      <th>2반</th>\n",
       "      <th>1반</th>\n",
       "      <th>2반</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>국</th>\n",
       "      <td>60.0</td>\n",
       "      <td>99.0</td>\n",
       "      <td>59.0</td>\n",
       "      <td>74.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>영</th>\n",
       "      <td>71.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>82.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>수</th>\n",
       "      <td>59.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>NaN</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "     1반    2반    1반    2반\n",
       "국  60.0  99.0  59.0  74.0\n",
       "영  71.0  69.0  50.0  82.0\n",
       "수  59.0  69.0   NaN  70.0"
      ]
     },
     "execution_count": 37,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.T    # 행과 열을 바꿈"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 38,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "       국     영     수\n",
       "1반  60.0  71.0  59.0\n",
       "2반  99.0  69.0  69.0\n",
       "1반  59.0  50.0   NaN\n",
       "2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 38,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 39,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th rowspan=\"2\" valign=\"top\">1학년</th>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th rowspan=\"2\" valign=\"top\">2학년</th>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "           국     영     수\n",
       "1학년 1반  60.0  71.0  59.0\n",
       "    2반  99.0  69.0  69.0\n",
       "2학년 1반  59.0  50.0   NaN\n",
       "    2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 39,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.index=[['1학년','1학년','2학년','2학년'],\n",
    "          ['1반','2반','1반','2반']]    # .index() 인덱스(행) 구분을 추가\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 40,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead tr th {\n",
       "        text-align: left;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th colspan=\"2\" halign=\"left\">언어</th>\n",
       "      <th>수리</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th rowspan=\"2\" valign=\"top\">1학년</th>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th rowspan=\"2\" valign=\"top\">2학년</th>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "          언어          수리\n",
       "           국     영     수\n",
       "1학년 1반  60.0  71.0  59.0\n",
       "    2반  99.0  69.0  69.0\n",
       "2학년 1반  59.0  50.0   NaN\n",
       "    2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 40,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.columns=[['언어','언어','수리'],['국','영','수']]    # .columns() 컬럼(열) 구분을 추가\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 41,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "1학년  1반    60.0\n",
       "     2반    99.0\n",
       "2학년  1반    59.0\n",
       "     2반    74.0\n",
       "Name: 국, dtype: float64"
      ]
     },
     "execution_count": 41,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df['언어']['국']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 42,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "언어  국    60.0\n",
       "    영    71.0\n",
       "수리  수    59.0\n",
       "Name: (1학년, 1반), dtype: float64"
      ]
     },
     "execution_count": 42,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.iloc[0]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
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       "    }\n",
       "\n",
       "    .dataframe thead tr th {\n",
       "        text-align: left;\n",
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       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th colspan=\"2\" halign=\"left\">언어</th>\n",
       "      <th>수리</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "      언어          수리\n",
       "       국     영     수\n",
       "1반  60.0  71.0  59.0\n",
       "2반  99.0  69.0  69.0"
      ]
     },
     "execution_count": 43,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.loc['1학년']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 44,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "언어  국    60.0\n",
       "    영    71.0\n",
       "수리  수    59.0\n",
       "Name: 1반, dtype: float64"
      ]
     },
     "execution_count": 44,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.loc['1학년'].loc['1반']"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 데이터 사전 분석\n",
    "\n",
    "- info() : DataFrame을 구성하는 행과 열에 대한 정보를 나타내 주는 함수\n",
    "- head(n) : DataFrame의 처음부터 n줄의 행을 출력\n",
    "- tail(n) : DataFrame의 마지막 n줄의 행을 출력\n",
    "- describe() : Series, DataFrame의 각 열에 대한 요약 통계\n",
    "- dtypes : 데이터 자료형 확인"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead tr th {\n",
       "        text-align: left;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th colspan=\"2\" halign=\"left\">언어</th>\n",
       "      <th>수리</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th rowspan=\"2\" valign=\"top\">1학년</th>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th rowspan=\"2\" valign=\"top\">2학년</th>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "          언어          수리\n",
       "           국     영     수\n",
       "1학년 1반  60.0  71.0  59.0\n",
       "    2반  99.0  69.0  69.0\n",
       "2학년 1반  59.0  50.0   NaN\n",
       "    2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 45,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 56,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "<class 'pandas.core.frame.DataFrame'>\n",
      "MultiIndex: 4 entries, ('1학년', '1반') to ('2학년', '2반')\n",
      "Data columns (total 3 columns):\n",
      " #   Column   Non-Null Count  Dtype  \n",
      "---  ------   --------------  -----  \n",
      " 0   (언어, 국)  4 non-null      float64\n",
      " 1   (언어, 영)  4 non-null      float64\n",
      " 2   (수리, 수)  3 non-null      float64\n",
      "dtypes: float64(3)\n",
      "memory usage: 248.0+ bytes\n"
     ]
    }
   ],
   "source": [
    "df.info()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 57,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead tr th {\n",
       "        text-align: left;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th colspan=\"2\" halign=\"left\">언어</th>\n",
       "      <th>수리</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th rowspan=\"2\" valign=\"top\">1학년</th>\n",
       "      <th>1반</th>\n",
       "      <td>60.0</td>\n",
       "      <td>71.0</td>\n",
       "      <td>59.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>99.0</td>\n",
       "      <td>69.0</td>\n",
       "      <td>69.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "          언어          수리\n",
       "           국     영     수\n",
       "1학년 1반  60.0  71.0  59.0\n",
       "    2반  99.0  69.0  69.0"
      ]
     },
     "execution_count": 57,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.head(2)    # 매개변수 없으면, 전부 출력"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 60,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead tr th {\n",
       "        text-align: left;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th colspan=\"2\" halign=\"left\">언어</th>\n",
       "      <th>수리</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th rowspan=\"2\" valign=\"top\">2학년</th>\n",
       "      <th>1반</th>\n",
       "      <td>59.0</td>\n",
       "      <td>50.0</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2반</th>\n",
       "      <td>74.0</td>\n",
       "      <td>82.0</td>\n",
       "      <td>70.0</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "          언어          수리\n",
       "           국     영     수\n",
       "2학년 1반  59.0  50.0   NaN\n",
       "    2반  74.0  82.0  70.0"
      ]
     },
     "execution_count": 60,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.tail(2)    # 매개변수 없으면, 전부 출력"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 61,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead tr th {\n",
       "        text-align: left;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th colspan=\"2\" halign=\"left\">언어</th>\n",
       "      <th>수리</th>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th></th>\n",
       "      <th>국</th>\n",
       "      <th>영</th>\n",
       "      <th>수</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>count</th>\n",
       "      <td>4.000000</td>\n",
       "      <td>4.000000</td>\n",
       "      <td>3.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>mean</th>\n",
       "      <td>73.000000</td>\n",
       "      <td>68.000000</td>\n",
       "      <td>66.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>std</th>\n",
       "      <td>18.636881</td>\n",
       "      <td>13.291601</td>\n",
       "      <td>6.082763</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>min</th>\n",
       "      <td>59.000000</td>\n",
       "      <td>50.000000</td>\n",
       "      <td>59.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>25%</th>\n",
       "      <td>59.750000</td>\n",
       "      <td>64.250000</td>\n",
       "      <td>64.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>50%</th>\n",
       "      <td>67.000000</td>\n",
       "      <td>70.000000</td>\n",
       "      <td>69.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>75%</th>\n",
       "      <td>80.250000</td>\n",
       "      <td>73.750000</td>\n",
       "      <td>69.500000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>max</th>\n",
       "      <td>99.000000</td>\n",
       "      <td>82.000000</td>\n",
       "      <td>70.000000</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "              언어                    수리\n",
       "               국          영          수\n",
       "count   4.000000   4.000000   3.000000\n",
       "mean   73.000000  68.000000  66.000000\n",
       "std    18.636881  13.291601   6.082763\n",
       "min    59.000000  50.000000  59.000000\n",
       "25%    59.750000  64.250000  64.000000\n",
       "50%    67.000000  70.000000  69.000000\n",
       "75%    80.250000  73.750000  69.500000\n",
       "max    99.000000  82.000000  70.000000"
      ]
     },
     "execution_count": 61,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.describe()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 62,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "언어  국    float64\n",
       "    영    float64\n",
       "수리  수    float64\n",
       "dtype: object"
      ]
     },
     "execution_count": 62,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df.dtypes"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 값의 연결\n",
    "\n",
    "- concat : DataFrame끼리 결합\n",
    "- axis=0 or 1 : 아래로 데이터 연결 / 옆으로 데이터 연결\n",
    "- append : 마지막 행에 데이터를 추가 \n",
    "    - ※ concatenate : 배열끼리 결합"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 64,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>0</th>\n",
       "      <th>1</th>\n",
       "      <th>2</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>2</td>\n",
       "      <td>3</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>4</td>\n",
       "      <td>5</td>\n",
       "      <td>6</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>7</td>\n",
       "      <td>8</td>\n",
       "      <td>9</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   0  1  2\n",
       "0  1  2  3\n",
       "1  4  5  6\n",
       "2  7  8  9"
      ]
     },
     "execution_count": 64,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a=pd.DataFrame(np.arange(1,10).reshape(3,3))\n",
    "a"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 65,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0    10\n",
       "1    20\n",
       "2    30\n",
       "dtype: int32"
      ]
     },
     "execution_count": 65,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "b=pd.Series(np.arange(10,40,10))\n",
    "b"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 66,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>0</th>\n",
       "      <th>1</th>\n",
       "      <th>2</th>\n",
       "      <th>0</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>2</td>\n",
       "      <td>3</td>\n",
       "      <td>10</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>4</td>\n",
       "      <td>5</td>\n",
       "      <td>6</td>\n",
       "      <td>20</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>7</td>\n",
       "      <td>8</td>\n",
       "      <td>9</td>\n",
       "      <td>30</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   0  1  2   0\n",
       "0  1  2  3  10\n",
       "1  4  5  6  20\n",
       "2  7  8  9  30"
      ]
     },
     "execution_count": 66,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pd.concat([a,b], axis=1)   # 0:행, 1: 열"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 67,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
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       "    .dataframe tbody tr th {\n",
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       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
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       "      <th>3</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
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       "      <td>3</td>\n",
       "      <td>10</td>\n",
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       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>4</td>\n",
       "      <td>5</td>\n",
       "      <td>6</td>\n",
       "      <td>20</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>7</td>\n",
       "      <td>8</td>\n",
       "      <td>9</td>\n",
       "      <td>30</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   0  1  2   3\n",
       "0  1  2  3  10\n",
       "1  4  5  6  20\n",
       "2  7  8  9  30"
      ]
     },
     "execution_count": 67,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "pd.concat([a,b], axis=1,ignore_index=True)  # False는 열 이름 그대로 둔다(0), True는 3으로 변경한다"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 68,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>0</th>\n",
       "      <th>1</th>\n",
       "      <th>2</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>1</td>\n",
       "      <td>2</td>\n",
       "      <td>3</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>4</td>\n",
       "      <td>5</td>\n",
       "      <td>6</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>7</td>\n",
       "      <td>8</td>\n",
       "      <td>9</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>10</td>\n",
       "      <td>20</td>\n",
       "      <td>30</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "    0   1   2\n",
       "0   1   2   3\n",
       "1   4   5   6\n",
       "2   7   8   9\n",
       "3  10  20  30"
      ]
     },
     "execution_count": 68,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "a.append(b, ignore_index=True)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 엑셀파일과 연동\n",
    "\n",
    "- ExeclFile(파일명) : 엑셀파일을 불러오기 \n",
    "- to_excel() : 엑셀파일로 내보내기"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 73,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>name</th>\n",
       "      <th>kor</th>\n",
       "      <th>eng</th>\n",
       "      <th>mat</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>A</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>B</td>\n",
       "      <td>100</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>C</td>\n",
       "      <td>80</td>\n",
       "      <td>100</td>\n",
       "      <td>55</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>D</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>E</td>\n",
       "      <td>80</td>\n",
       "      <td>55</td>\n",
       "      <td>55</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>F</td>\n",
       "      <td>55</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>G</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>H</td>\n",
       "      <td>55</td>\n",
       "      <td>80</td>\n",
       "      <td>100</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>I</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>J</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>100</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10</th>\n",
       "      <td>K</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>L</td>\n",
       "      <td>47</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>12</th>\n",
       "      <td>M</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>N</td>\n",
       "      <td>100</td>\n",
       "      <td>80</td>\n",
       "      <td>55</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>14</th>\n",
       "      <td>O</td>\n",
       "      <td>80</td>\n",
       "      <td>65</td>\n",
       "      <td>100</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   name  kor  eng  mat\n",
       "0     A   80   80   80\n",
       "1     B  100   80   80\n",
       "2     C   80  100   55\n",
       "3     D   80   80   80\n",
       "4     E   80   55   55\n",
       "5     F   55   80   80\n",
       "6     G   80   80   80\n",
       "7     H   55   80  100\n",
       "8     I   80   80   80\n",
       "9     J   80   80  100\n",
       "10    K   80   80   80\n",
       "11    L   47   80   80\n",
       "12    M   80   80   80\n",
       "13    N  100   80   55\n",
       "14    O   80   65  100"
      ]
     },
     "execution_count": 73,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "\n",
    "import pandas as pd\n",
    "\n",
    "file='test.xls'\n",
    "xl=pd.ExcelFile(file)    # 불러오기\n",
    "df=xl.parse('Sheet1')\n",
    "\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 74,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "(15, 4)\n",
      "Index(['name', 'kor', 'eng', 'mat'], dtype='object')\n"
     ]
    }
   ],
   "source": [
    "print(df.shape)\n",
    "print(df.columns)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 80,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "['A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O']\n",
      "[80, 100, 80, 80, 80, 55, 80, 55, 80, 80, 80, 47, 80, 100, 80]\n",
      "[80, 80, 100, 80, 55, 80, 80, 80, 80, 80, 80, 80, 80, 80, 65]\n",
      "[80, 80, 55, 80, 55, 80, 80, 100, 80, 100, 80, 80, 80, 55, 100]\n",
      "[240, 260, 235, 240, 190, 215, 240, 235, 240, 260, 240, 207, 240, 235, 245]\n",
      "[80.0, 86.66666666666667, 78.33333333333333, 80.0, 63.333333333333336, 71.66666666666667, 80.0, 78.33333333333333, 80.0, 86.66666666666667, 80.0, 69.0, 80.0, 78.33333333333333, 81.66666666666667]\n"
     ]
    }
   ],
   "source": [
    "name=[]\n",
    "kor=[]\n",
    "eng=[]\n",
    "mat=[]\n",
    "tot=[]\n",
    "avg=[]\n",
    "for i, col in df.iterrows():\n",
    "    name.append(col[0])\n",
    "    kor.append(col[1])\n",
    "    eng.append(col[2])\n",
    "    mat.append(col[3])\n",
    "    tot.append(sum(col[1:]))\n",
    "    avg.append(sum(col[1:]) / 3)\n",
    "    \n",
    "\n",
    "print(name)\n",
    "print(kor)\n",
    "print(eng)\n",
    "print(mat)\n",
    "print(tot)\n",
    "print(avg)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 82,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>이름</th>\n",
       "      <th>국어</th>\n",
       "      <th>영어</th>\n",
       "      <th>수학</th>\n",
       "      <th>총점</th>\n",
       "      <th>평균</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>A</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>240</td>\n",
       "      <td>80.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>B</td>\n",
       "      <td>100</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>260</td>\n",
       "      <td>86.666667</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>C</td>\n",
       "      <td>80</td>\n",
       "      <td>100</td>\n",
       "      <td>55</td>\n",
       "      <td>235</td>\n",
       "      <td>78.333333</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>D</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>240</td>\n",
       "      <td>80.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>E</td>\n",
       "      <td>80</td>\n",
       "      <td>55</td>\n",
       "      <td>55</td>\n",
       "      <td>190</td>\n",
       "      <td>63.333333</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>5</th>\n",
       "      <td>F</td>\n",
       "      <td>55</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>215</td>\n",
       "      <td>71.666667</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>6</th>\n",
       "      <td>G</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>240</td>\n",
       "      <td>80.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>7</th>\n",
       "      <td>H</td>\n",
       "      <td>55</td>\n",
       "      <td>80</td>\n",
       "      <td>100</td>\n",
       "      <td>235</td>\n",
       "      <td>78.333333</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>8</th>\n",
       "      <td>I</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>240</td>\n",
       "      <td>80.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>9</th>\n",
       "      <td>J</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>100</td>\n",
       "      <td>260</td>\n",
       "      <td>86.666667</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>10</th>\n",
       "      <td>K</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>240</td>\n",
       "      <td>80.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>11</th>\n",
       "      <td>L</td>\n",
       "      <td>47</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>207</td>\n",
       "      <td>69.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>12</th>\n",
       "      <td>M</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>80</td>\n",
       "      <td>240</td>\n",
       "      <td>80.000000</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>13</th>\n",
       "      <td>N</td>\n",
       "      <td>100</td>\n",
       "      <td>80</td>\n",
       "      <td>55</td>\n",
       "      <td>235</td>\n",
       "      <td>78.333333</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>14</th>\n",
       "      <td>O</td>\n",
       "      <td>80</td>\n",
       "      <td>65</td>\n",
       "      <td>100</td>\n",
       "      <td>245</td>\n",
       "      <td>81.666667</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "</div>"
      ],
      "text/plain": [
       "   이름   국어   영어   수학   총점         평균\n",
       "0   A   80   80   80  240  80.000000\n",
       "1   B  100   80   80  260  86.666667\n",
       "2   C   80  100   55  235  78.333333\n",
       "3   D   80   80   80  240  80.000000\n",
       "4   E   80   55   55  190  63.333333\n",
       "5   F   55   80   80  215  71.666667\n",
       "6   G   80   80   80  240  80.000000\n",
       "7   H   55   80  100  235  78.333333\n",
       "8   I   80   80   80  240  80.000000\n",
       "9   J   80   80  100  260  86.666667\n",
       "10  K   80   80   80  240  80.000000\n",
       "11  L   47   80   80  207  69.000000\n",
       "12  M   80   80   80  240  80.000000\n",
       "13  N  100   80   55  235  78.333333\n",
       "14  O   80   65  100  245  81.666667"
      ]
     },
     "execution_count": 82,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "from pandas import DataFrame\n",
    "\n",
    "raw_data={\n",
    "    '이름':name,\n",
    "    '국어':kor,\n",
    "    '영어':eng,\n",
    "    '수학':mat,\n",
    "    '총점':tot,\n",
    "    '평균':avg\n",
    "}\n",
    "\n",
    "data=DataFrame(raw_data)\n",
    "data.to_excel(\"test2.xls\",sheet_name='Sheet2.xls', encoding='utf-8')    # 내보내기\n",
    "data"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.7.6"
  }
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 "nbformat": 4,
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