Platform independent path concatenation using "/" , "\"?

Question

In python I have variables base_dir and filename. I would like to concatenate them to obtain fullpath. But under windows I should use \ and for POSIX / .

fullpath = "%s/%s" % ( base_dir, filename ) # for Linux 

How can I make this platform independent?

Answer 1

You want to use os.path.join() for this.

The strength of using this rather than string concatenation etc is that it is aware of the various OS specific issues, such as path separators. Examples:

import os 

Under Windows 7:

base_dir = r'c:\bla\bing' filename = r'data.txt'  os.path.join(base_dir, filename) 'c:\\bla\\bing\\data.txt' 

Under Linux:

base_dir = '/bla/bing' filename = 'data.txt'  os.path.join(base_dir, filename) '/bla/bing/data.txt' 

The os module contains many useful methods for directory, path manipulation and finding out OS specific information, such as the separator used in paths via os.sep

Answer 2

Use os.path.join():

import os fullpath = os.path.join(base_dir, filename) 

The os.path module contains all of the methods you should need for platform independent path manipulation, but in case you need to know what the path separator is on the current platform you can use os.sep.