What is the correct cross-platform way to get the home directory in Python? – Dev

The best answers to the question “What is the correct cross-platform way to get the home directory in Python?” in the category Dev.

QUESTION:

I need to get the location of the home directory of the current logged-on user. Currently, I’ve been using the following on Linux:

os.getenv("HOME")

However, this does not work on Windows. What is the correct cross-platform way to do this ?

ANSWER:

I found that pathlib module also supports this.

from pathlib import Path
>>> Path.home()
WindowsPath('C:/Users/XXX')

ANSWER:

You want to use os.path.expanduser.
This will ensure it works on all platforms:

from os.path import expanduser
home = expanduser("~")

If you’re on Python 3.5+ you can use pathlib.Path.home():

from pathlib import Path
home = str(Path.home())

ANSWER:

This doesn’t really qualify for the question (it being tagged as cross-platform), but perhaps this could be useful for someone.

How to get the home directory for effective user (Linux specific).

Let’s imagine that you are writing an installer script or some other solution that requires you to perform certain actions under certain local users. You would most likely accomplish this in your installer script by changing the effective user, but os.path.expanduser("~") will still return /root.

The argument needs to have the desired user name:

os.path.expanduser(f"~{USERNAME}/")

Note that the above works fine without changing EUID, but if the scenario previously described would apply, the example below shows how this could be used:

import os
import pwd
import grp

class Identity():

    def __init__(self, user: str, group: str = None):
        self.uid = pwd.getpwnam(user).pw_uid
        if not group:
            self.gid = pwd.getpwnam(user).pw_gid
        else:
            self.gid = grp.getgrnam(group).gr_gid

    def __enter__(self):
        self.original_uid = os.getuid()
        self.original_gid = os.getgid()
        os.setegid(self.uid)
        os.seteuid(self.gid)

    def __exit__(self, type, value, traceback):
        os.seteuid(self.original_uid)
        os.setegid(self.original_gid)

if __name__ == '__main__':

    with Identity("hedy", "lamarr"):
        homedir = os.path.expanduser(f"~{pwd.getpwuid(os.geteuid())[0]}/")
        with open(os.path.join(homedir, "install.log"), "w") as file:
            file.write("Your home directory contents have been altered")

ANSWER:

I know this is an old thread, but I recently needed this for a large scale project (Python 3.8). It had to work on any mainstream OS, so therefore I went with the solution @Max wrote in the comments.

Code:

import os
print(os.path.expanduser("~"))

Output Windows:

PS C:\Python> & C:/Python38/python.exe c:/Python/test.py
C:\Users\mXXXXX

Output Linux (Ubuntu):

[email protected]:/mnt/c/Python$ python3 test.py
/home/rxxx

I also tested it on Python 2.7.17 and that works too.