2.6Combining Turnstile Data.py

import pandas
def create_master_turnstile_file(filenames, output_file):
    '''
    Write a function that takes the files in the list filenames, which all have the 
    columns 'C/A, UNIT, SCP, DATEn, TIMEn, DESCn, ENTRIESn, EXITSn', and consolidates
    them into one file located at output_file.  There should be ONE row with the column
    headers, located at the top of the file.
    
    For example, if file_1 has:
    'C/A, UNIT, SCP, DATEn, TIMEn, DESCn, ENTRIESn, EXITSn'
    line 1 ...
    line 2 ...
    
    and another file, file_2 has:
    'C/A, UNIT, SCP, DATEn, TIMEn, DESCn, ENTRIESn, EXITSn'
    line 3 ...
    line 4 ...
    line 5 ...
    
    We need to combine file_1 and file_2 into a master_file like below:
     'C/A, UNIT, SCP, DATEn, TIMEn, DESCn, ENTRIESn, EXITSn'
    line 1 ...
    line 2 ...
    line 3 ...
    line 4 ...
    line 5 ...
    '''
    with open(output_file, 'w') as master_file:
       master_file.write('C/A,UNIT,SCP,DATEn,TIMEn,DESCn,ENTRIESn,EXITSn\n')
       for filename in filenames:
            turnstyle_data = pandas.read_csv(filename)
            turnstyle_data.to_csv(master_file, index=False)