which one should I use: os.sep or os.path.sep?

Question

They are same, but which one should I use?

http://docs.python.org/library/os.html:

os.sep

The character used by the operating system to separate pathname components. This is '/' for POSIX and '\' for Windows. Note that knowing this is not sufficient to be able to parse or concatenate pathnames — use os.path.split() and os.path.join() — but it is occasionally useful. Also available via os.path.

Answer 1

I recommend you use os.path.sep for clarity, since it's a path separator, not an OS separator. If you import os.path as path you can call it path.sep, which is even better.

Answer 2

If you are using Python 2.7, I suggest using os.sep (works) instead of os.path.sep (broken) as Jython on Windows has a bug returning a "/" slash instead of the required "\" backslash.

Answer 3

The following examples could highlight the differences between os.path.join and os.path.sep.join.

>>> import os
>>> os.path.join("output", "images", "saved")
'output/images/saved'
>>> os.path.sep.join(["output", "images", "saved"])
'output/images/saved'

I guess the os.path.sep.join is more robust and can be used w/o modifications for any os.

Answer 4

1. As mentioned in the python docs, both os.path.sep and os.sep return the same output.

The character used by the operating system to separate pathname components. This is '/' for POSIX and '\' for Windows.

2. Both of them belongs to the same python class also.

   print(type(os.sep))
   print(type(os.path.sep))
   
   # Output
   <class 'str'>
   <class 'str'>
   

3. Both have them have the same documentation.

   print(os.path.sep.__doc__)
   print(os.sep.__doc__)
   
   # The outputs of both print statements are the same. 
   

So, I think after Python2 where we mostly used os.sep, in Python3 only the consistency matters as far as their uses are concerned.