Rename files to instead being in sub-directories, have the year as part of the filename

Question

Create a copy of the CarItems tree called CarItemsCopy where all files, instead of being in directories named after years, rather have the year as part of the filename, and the

Answer 1

You do need the walk to get to all the filenames, though you can directly figure out the new filenames.

The psuedocode:

# Make a list of filenames with os.walk
# For each filename in that list:
#    If the filename matches a regex of ending with four digits, slash, name
#        make the new filename
#        use os.rename to move the original file to the new file.

You need to make a separate list rather than just for name in os.walk... because we will be changing the contents as we go.

Creating a regex with Regex101, we get a solution. You may want to try it yourself before looking at this:

import os
import re


pattern = r'(.*)(\\|/)(\d\d\d\d)(\\|/)(\w+)(\.txt)'
             # Note r'..' means raw, or take backslashes literally so the regex is correct.
filenames = [ os.path.join(dir_, name)
              for (dir_, _, names) in os.walk('.')
                  for name in names ]
             # Note 'dir_' because dir is reserved word
             # Note '_' as pythonic way of saying 'an ignored value'
             # Note for loops are in same order in list comprehension as they would be in code

for filename in filenames:
    m = re.match(pattern, filename)
    if m:
        front, sep1, year, sep2, name, ext = m.groups()
        new_filename = f'{front}{sep1}{name}-{year}{ext}'
        # print(f'rename {filename} to {new_filename}')
        os.rename(filename, new_filename)

Keep Hacking! Keep notes.