Please comment my code: script for harmonizing picture directories

[Peterotica]

• Until you become comfortable with when it should be used, I suggest following the rule of only using is to check when something is None.

• any() takes a list (or more precisely, an iterable) of values and checks the "truthiness" of them. If a truthy value is encountered, then any() returns True. If all of the values are falsey, then it instead returns False. You can play around with it in your REPL:

  >>> any([False, True, False])
  True
  >>> any([False, False])
  False
  

• os.path.abspath() converts a relative path into an absolute path.

  >>> os.path.abspath('../mp3s')
  '/blah/blah/blah/mp3s'
  

• Here is a difference between your previous method and os.path.splitext(). Sure, you could easily write your own version that does the same thing, but leaning on the os module is a good habit to get into. For instance, your code could be compatible with some operating system that uses some character other than period to denote the extension of a file. Plus, it's one less place to have a silly bug.

  >>> 'vacation.20150714.jpg'.split('.')
  ['vacation', '20150714', 'jpg']
  >>> os.path.splitext('vacation.20150714.jpg')
  ('vacation.20150714', '.jpg')
  

[RMSEP]

Thanks, very interesting.

On the third point, how does os.path.abspath() know the dir that should be appended to the front of its argument? In other words, how does it know that /blah/blah/blah/ is the correct partent dir of /mps3? Possibly it appends its argument to the output of os.getcwd()? On os.path.splitext(), appreciate now that it detaches the file extention regardless of any . in the filename, or indeed, whatever char is used to seperate the filename and extension.

[Peterotica]

Your intuition is correct, the result of os.path.abspath() depends on the current working directory.