Python: Getting AppData folder in a cross-platform way

Question

I\'d like a code snippet that gets the proper directory for app data (config files, etc) on all platforms (Win/Mac/Linux at least). For example: %APPDATA%/ on Windows.

Answer 1

Qt's QStandardPaths documentation lists paths like this.

Using Python 3.8

import sys
import pathlib

def get_datadir() -> pathlib.Path:

    """
    Returns a parent directory path
    where persistent application data can be stored.

    # linux: ~/.local/share
    # macOS: ~/Library/Application Support
    # windows: C:/Users/<USER>/AppData/Roaming
    """

    home = pathlib.Path.home()

    if sys.platform == "win32":
        return home / "AppData/Roaming"
    elif sys.platform == "linux":
        return home / ".local/share"
    elif sys.platform == "darwin":
        return home / "Library/Application Support"

# create your program's directory

my_datadir = get_datadir() / "program-name"

try:
    my_datadir.mkdir(parents=True)
except FileExistsError:
    pass

The Python documentation recommends the sys.platform.startswith('linux') "idiom" for compatibility with older versions of Python that returned things like "linux2" or "linux3".

Answer 2

If you don't mind using the appdirs module, it should solve your problem. (cost = you either need to install the module or include it directly in your Python application.)

Answer 3

I recommend researching the locations of 'appdata' in the operating systems that you want to use this program on. Once you know the locations you could simple use if statements to detect the os and do_something().

import sys
if sys.platform == "platform_value":
    do_something()
elif sys.platform == "platform_value":
    do_something()

• System: platform_value
• Linux (2.x and 3.x): 'linux2'
• Windows: 'win32'
• Windows/Cygwin: 'cygwin'
• Mac OS X: 'darwin'
• OS/2: 'os2'
• OS/2 EMX: 'os2emx'
• RiscOS: 'riscos'
• AtheOS: 'atheos'

List is from the official Python docs. (Search for 'sys.platform')

Answer 4

You can use the following function to get user data dir, tested in linux and w10 (returning AppData/Local dir) it's adapted from the appdirs package:

import sys
from pathlib import Path
from os import getenv

def get_user_data_dir(appname):
    if sys.platform == "win32":
        import winreg
        key = winreg.OpenKey(
            winreg.HKEY_CURRENT_USER,
            r"Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders"
        )
        dir_,_ = winreg.QueryValueEx(key, "Local AppData")
        ans = Path(dir_).resolve(strict=False)
    elif sys.platform == 'darwin':
        ans = Path('~/Library/Application Support/').expanduser()
    else:
        ans=Path(getenv('XDG_DATA_HOME', "~/.local/share")).expanduser()
    return ans.joinpath(appname)