DS101-02-PS-02-create_master_turnstile_file.py

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:
            # open the file
            with open(filename, 'rb') as f:
                firstline = True
                for line in f:
                    # skip first line
                    if firstline:
                        firstline = False
                        continue
                    # write the rest to master output file
                    master_file.write(line)