Automate backup file maintenance with Python

I automated my disk backups, but I kept having to delete the extra backup files manually so I wouldn't run out of space.  I decided I needed to automate that task as well.

Add the following Python script to a task so it will run automatically.

Python script:
import os
import datetime
import fnmatch

dir_to_search = "[full path to backup directory]"
for dirpath, dirnames, filenames in os.walk(dir_to_search):
   intCountOfTotalBackups = len(fnmatch.filter(filenames, '[Backup name, same as the Macrium XML file]*-00-00.mrimg'))
   print "Total Backups: " + str(intCountOfTotalBackups)
   intCountOfBackupsToDelete = 0
 
   for file in fnmatch.filter(filenames, '[Backup name, same as the Macrium XML file]*-00-00.mrimg'):
      curpath = os.path.join(dirpath, file)
      file_modified = datetime.datetime.fromtimestamp(os.path.getmtime(curpath))
      #keep a weeks worth of backups
      if datetime.datetime.now() - file_modified > datetime.timedelta(hours=168):
          intCountOfBackupsToDelete += 1

   print intCountOfBackupsToDelete
   #always keep at least a few backups, even if they are old.
   if intCountOfBackupsToDelete < (intCountOfTotalBackups - 4):
      print str(intCountOfBackupsToDelete) + ' < ' + str(intCountOfTotalBackups - 4)
      for file in fnmatch.filter(filenames, 'Atom_Nightly*-00-00.mrimg'):
         curpath = os.path.join(dirpath, file)
         file_modified = datetime.datetime.fromtimestamp(os.path.getmtime(curpath))
         if datetime.datetime.now() - file_modified > datetime.timedelta(hours=168):
             os.remove(curpath)
             print "remove " + curpath
#input("Press Enter to continue...")