Question

If I use filename = argv[n] from a windows command line, the extract() function below seems to work okay. If I instead use the list of files names from the list(dir), which uses the os.listdir() built-in function to extract the filenames from the working directory, then the extract() function fails.

The input_file.read() recognises the filename as a valid value, but it seems to fail at date = list(date_match[0]) with ‘TypeError: coercing to Unicode: need string or buffer, tuple found’.

It seems that the os.listdir output list values are not normal strings, but something else instead. Any ideas?

import sys
import re
import os

def extract(filename):

    input_file = open(filename, 'r')
    data = input_file.read() #read file line by line

    #make list of time and date
    date_match = re.findall(r'(\d+:\d+)\t(\d+/\d+/\d+)', data) #find file date and time
    date = list(date_match[0])

    #extract date tuple from list above
    return date

def list(dir):
    directoryfiles = os.listdir(dir)
    diroutput = []
    for member in directoryfiles:
        if member != sys.argv[0]:
            diroutput.append(member)
    return diroutput

def main():

    inputfiles = list(sys.argv[1])

    for filename in inputfiles:
        date = extract(filename)

if __name__ == '__main__':
    main()

Answer 1

You’ve redefined list! When you try to do date = list(date_match[0]), you’re calling your list function, not the builtin list function. Rename the list function and it should work fine.