Pands.py

import pandas as pd
#重點 merge
name = ["蒙其·D·魯夫", "羅羅亞·索隆", "娜美", "騙人布", "賓什莫克·香吉士", "多尼多尼·喬巴", "妮可·羅賓", "佛朗基", "布魯克"]
occupation = ["船長", "劍士", "航海士", "狙擊手", "廚師", "醫生", "考古學家", "船匠", "音樂家"]

# 建立 dict
straw_hat_dict = {"name": name,
                  "occupation": occupation
}

# 建立第一個 data frame
straw_hat_df = pd.DataFrame(straw_hat_dict)

name = ["蒙其·D·魯夫", "多尼多尼·喬巴", "妮可·羅賓", "布魯克"]
devil_fruit = ["橡膠果實", "人人果實", "花花果實", "黃泉果實"]

# 建立 dict
devil_fruit_dict = {"name": name,
                    "devil_fruit": devil_fruit
}

# 建立第二個 data frame
devil_fruit_df = pd.DataFrame(devil_fruit_dict)

# 連接
straw_hat_merged = pd.merge(straw_hat_df, devil_fruit_df, how = "right")#左右代表取方向為標準
#取共通的陣列名,左右決定採用何者以他的行數為標準
print(straw_hat_merged)
#********************************************************************
#重點 添加資料 橫向 完整1人資料 or 縱向單一資料<每人都有一份
name = ["娜菲鲁塔利·薇薇"]
occupation = ["阿拉巴斯坦王國公主"]
princess_vivi_dict = {"name": name,
                      "occupation": occupation
}


princess_vivi_df = pd.DataFrame(princess_vivi_dict, index = [len(straw_hat_df)])#*

# 新增一個觀測值!
straw_hat_df_w_vivi = pd.concat([straw_hat_df, princess_vivi_df],axis=0)# 主 客
print(straw_hat_df_w_vivi)

age = [19, 21, 20, 19, 21, 17, 30, 36, 90, 18]
age_dict = {"age": age
}

# 建立第三個 data frame
age_df = pd.DataFrame(age_dict)

# 新增一個變數欄位!
straw_hat_df_w_vivi_age = pd.concat([straw_hat_df_w_vivi, age_df], axis = 1)
print(straw_hat_df_w_vivi_age.stack())#此方法把資料結構變成長的
#*************************************************************************
'''去除重複值'''
# 建立一個有重複值的 data frame
name = ["蒙其·D·魯夫", "蒙其·D·魯夫", "蒙其·D·魯夫", "羅羅亞·索隆", "羅羅亞·索隆", "羅羅亞·索隆"]
age = [19, 19, 17, 21, 21, 19]
duplicated_dict = {
    "name": name,
    "age": age
}
duplicated_df = pd.DataFrame(duplicated_dict)

# 判斷是否重複
print(duplicated_df.duplicated())

# 去除重複觀測值
print(duplicated_df.drop_duplicates())
#**************************************************************************
#重點分別資料,小技巧ix可以更改 也可以增加
name = ["蒙其·D·魯夫", "羅羅亞·索隆", "娜美", "騙人布", "賓什莫克·香吉士", "多尼多尼·喬巴", "妮可·羅賓", "佛朗基", "布魯克"]
age = [19, 21, 20, 19, 21, 17, 30, 36, 90]

# 建立 dict
straw_hat_dict = {
    "name": name,
    "age": age
}

# 建立一個 data frame
straw_hat_df = pd.DataFrame(straw_hat_dict)

# 分箱
bins = [0, 25, float("inf")]
group_names = ["小於 25 歲", "超過 25 歲"]
straw_hat_df.ix[:, "age_cat"] = pd.cut(straw_hat_df.ix[:, "age"], bins, labels = group_names)#這裡可以新創,也可以更改ex:straw_hat_df.ix[:, "age"]=?
print(straw_hat_df)
#***************************************************************************
#to_csv and to_json
name = ["蒙其·D·魯夫", "羅羅亞·索隆", "娜美", "騙人布", "賓什莫克·香吉士", "多尼多尼·喬巴", "妮可·羅賓", "佛朗基", "布魯克"]
age = [19, 21, 20, 19, 21, 17, 30, 36, 90]

# 建立 dict
straw_hat_dict = {
    "name": name,
    "age": age
}

# 建立一個 data frame
straw_hat_df = pd.DataFrame(straw_hat_dict)

# 輸出為 csv
straw_hat_df.to_csv("straw_hat.csv", index = False)

# 輸出為 JSON
straw_hat_df.to_json("straw_hat.json")