How to check if a path is absolute path or relative path in a cross-platform way with Python?

Question

os.path.isabs returns True if the path is absolute, False if not. The documentation says it works in windows (I can confirm it works in Linux personally).

os.path.isabs(my_path)

And if what you really want is the absolute path, don't bother checking to see if it is, just get the abspath:

import os

print os.path.abspath('.')

From python 3.4 pathlib is available.

In [1]: from pathlib import Path

In [2]: Path('..').is_absolute()
Out[2]: False

In [3]: Path('C:/').is_absolute()
Out[3]: True

In [4]: Path('..').resolve()
Out[4]: WindowsPath('C:/the/complete/path')

In [5]: Path('C:/').resolve()
Out[5]: WindowsPath('C:/')

Use os.path.isabs.

import os.path

os.path.isabs('/home/user')
True

os.path.isabs('user')
False

Actually I think none of the above answers addressed the real issue: cross-platform paths. What os.path does is load the OS dependent version of 'path' library. so the solution is to explicitly load the relevant (OS) path library:

import ntpath
import posixpath

ntpath.isabs("Z:/a/b/c../../H/I/J.txt")
    True
posixpath.isabs("Z:/a/b/c../../H/I/J.txt")
    False