What is a cross-platform way to get the home directory?

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:UsersmXXXXX

Output Linux (Ubuntu):

rxxx@xx:/mnt/c/Python$ python3 test.py
/home/rxxx

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

I found that pathlib module also supports this.

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

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")

This can be done using pathlib, which is part of the standard library, and treats paths as objects with methods, instead of strings.

• Path.expanduser()
• Path.home()

from pathlib import Path

home: str = str(Path('~').expanduser())