Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community!

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Python Python for File Systems Manipulation Purging

Any advice?

I am trying to iterate through the [] of files in the directory using os.listdir("backups") with the intention of trying to match the string to the date with the if conditional statement, then trying to remove any file that matches.

It's popping an error so I know I'm missing something.

import os

def delete_by_date(date):
    for file in os.listdir("backups"):
        if file[:9] == date:

1 Answer

Steven Parker
Steven Parker
224,848 Points

You're pretty close, but I can see two issues:

  • check the argument sample again, 9 may not be enough characters for the slice
  • these files are in the "backups" directory, not the current one, so the name will need to reflect that

Steven Parker Ok, I went ahead and tried to followed the advice on the two issues that you brought up.

Tried the following in the for loop, but, both showed errors:

os.listdir(os.getcwd()) and os.listdir(os.path.dirname(os.path.abspath('backups')))

Tried the following slices, also showed errors:

[:10] it popped up an error2 and [:8] it popped up same error as [:9]

Any other clue you are willing to give up?

Steven Parker
Steven Parker
224,848 Points

One of your slice choices was correct.

But it's not the "listdir" that needs modification, it was already doing the job of listing the directory. Yet when you perform the "remove", you'll need to modify the name to reflect the file and the directory it is in.

Alright, got them both.

"<directory>" and <filename> worked.

Thank you!