No way to override location of the folders on Windows

[ooroor]

Hi, and thanks for platformdirs.

After using the library in a cross-platform Python application, I've noticed that it ignores common environment variable overrides that define directory locations on most systems. This includes:

• TMPDIR, TEMP, TMP on Unix/Linux/macOS
• XDG_CONFIG_HOME, XDG_DATA_HOME, XDG_CACHE_HOME on Linux
• Any user-specified overrides for Documents, Downloads, etc.

Example: Temp Directory

import os
from platformdirs import PlatformDirs

os.environ["TMPDIR"] = "/custom/tmp"
dirs = PlatformDirs("MyApp", "MyCompany")

print(dirs.user_cache_dir)  # Does NOT reflect TMPDIR override

Compare that with:

import tempfile
print(tempfile.gettempdir())  # Respects TMPDIR

Example: XDG Override Ignored

export XDG_CONFIG_HOME=/tmp/testconfig
python -c "from platformdirs import PlatformDirs; print(PlatformDirs('a', 'b').user_config_dir)"
# Still prints ~/.config/a

---

Expected Behavior

platformdirs should:

• Use environment variable overrides as per platform conventions
• Match the behavior of tempfile.gettempdir() (for temp dirs)
• Match freedesktop spec on Linux (for XDG-based paths)

---

Current Result

The library hardcodes the path logic and doesn't reflect system/user overrides, making it unsuitable for any situation where the environment is customized — which is very common in packaging, CI/CD, containerized apps, multi-user systems, or advanced user environments.

---

Suggested Fix / Feature Request

1. Fall back to current logic only if the environment variable is unset.
2. Document clearly how the library deals with environment overrides.
3. Optionally expose a temp_dir property that uses tempfile.gettempdir().

---

Conclusion

In its current state, platformdirs is nearly useless for real-world use cases where configuration directories, data paths, or temporary locations are customized by the environment. I'd strongly suggest making it respect the standard overrides, or at least make this behavior configurable.

Thanks for considering this!

[gaborbernat]

In its current state, platformdirs is nearly useless for real-world use cases where configuration directories, data paths, or temporary locations are customized by the environment.

Please use more respectful tone.

platformdirs/src/platformdirs/unix.py

Line 76 in 39fc384

path = os.environ.get("XDG_CONFIG_HOME", "")

shows that we do respect XDG_CONFIG_HOME, so can't replicate your issue. You might want to attach a reproducible with a Docker image, and more importantly submit PRs where you find feature gaps.

[Hoernchen]

I disagree with the tone, but the message is not wrong: I ended up here because on Windows I'll basically have to patch it to accept overrides...

[ooroor]

Hi! Writing in a non-mother-tongue may have some unwanted side effect not intended. Sorry for that. But the fact remains, however, I got the wrong directory and could not use the library. Then I had to do a patch myself, implicitly testing for the OS running my SW. This kind of OS branching is generally not wanted in higher level applications and should be made transparent by libraries used. Therefore, I still suggest a change to the library. Mvh Øyvind Roth Idas vei 62 0981 Oslo Norway Mob.: 45 81 19 56 e-post: ***@***.***> ***@***.*** From: Hoernchen ***@***.***> Sent: torsdag 19. juni 2025 13:48 To: tox-dev/platformdirs ***@***.***> Cc: Øyvind Roth ***@***.***>; Author ***@***.***> Subject: Re: [tox-dev/platformdirs] platformdirs ignores environment overrides like TMPDIR, XDG_*, and is therefore unreliable (Issue #347) <https://avatars.githubusercontent.com/u/2532692?s=20&v=4> Hoernchen left a comment (tox-dev/platformdirs#347) <#347 (comment)> I disagree with the tone, but the message is not wrong: I ended up here because on Windows I'll basically have to patch it to accept overrides... — Reply to this email directly, view it on GitHub <#347 (comment)> , or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACLIRPJPYOFOFN6XVWYNUP33EKPQPAVCNFSM6AAAAAB2UUSXRSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDSOBXG44TKOBSGI> . You are receiving this because you authored the thread. <https://github.com/notifications/beacon/ACLIRPNRFGQFZ5GYY2ULMBT3EKPQPA5CNFSM6AAAAAB2UUSXRSWGG33NNVSW45C7OR4XAZNMJFZXG5LFINXW23LFNZ2KUY3PNVWWK3TUL5UWJTVSCYSW4.gif> Message ID: ***@***.*** ***@***.***> >

[jkseppan]

Cannot reproduce. On a Linux host I can override the config directory with XDG_CONFIG_HOME:

env XDG_CONFIG_HOME=/tmp/testconfig uv run --with platformdirs --with ipython ipython
Python 3.11.2 (main, Nov 30 2024, 21:22:50) [GCC 12.2.0]
Type 'copyright', 'credits' or 'license' for more information
IPython 9.3.0 -- An enhanced Interactive Python. Type '?' for help.
Tip: You can use `%hist` to view history, see the options with `%history?`

In [1]: from platformdirs import PlatformDirs

In [2]: print(PlatformDirs('a', 'b').user_config_dir)
/tmp/testconfig/a

[gaborbernat]

I don't think there's anything to be done here on Unix as you can already use XDG_CONFIG_HOME. I don't see why TMPDIR should overwrite platform defaults or XDG_CONFIG_HOME, XDG_DATA_HOME, XDG_CACHE_HOME on Linux.

For Windows, this is indeed a valid concern. Can someone do a research on what windows recommend to control this?

[gaborbernat]

A valid solution here would be to accept environment variables here https://github.com/tox-dev/platformdirs/blob/main/src/platformdirs/windows.py#L221 before reading the value from the registry. The variable name would be the registry key minus the CSDL_ prefix, so CSIDL_APPDATA would be change-able via APPDATA environment variable.

[Hoernchen]

Please keep in mind that the point is to override, not to actually change the windows env vars that are used by everything else! The env var APPDATA exists and is the actual appdata pointing at the user dirs, changing that is a bad idea!

This is for example what I'm doing for all kinds of other packages to redirect large amounts of data (the models are easily hundreds of gigabytes, the package cache is large as well) so they do not end up in my user profile:

    os.environ["PYANNOTE_CACHE"] = r"X:\aicache\annoc"
    os.environ["TORCH_HOME"] = r"X:\aicache\torchh"
    os.environ["DEEPFACE_HOME"] = r"X:\aicache\dfhome"
    os.environ["XDG_CACHE_HOME"] = r"X:\aicache\xdgc"
    os.environ["PIP_CACHE_DIR"] = r"X:\aicache\pipc"
    os.environ["PIP_DOWNLOAD_CACHE"] = r"X:\aicache\pipdlc"
    os.environ["TRANSFORMERS_CACHE"] = r"X:\aicache\tfc"
    os.environ["HF_HOME"] = r"X:\aicache\hfhome"
    os.environ["UV_CACHE_DIR"] = r"X:\aicache\uvcache"

This does not redirect APPDATA/LOCALAPPDATA/.. itself, that is still the default, and still automatically used for example for secret storage (access tokens for downlod) used by these packages, which is per-user data that should probably not end up somewhere else. As you can see it's a wild mix, but that is fine, as long as the specific var that has to be used is documented and easy to find.

The reason why I ended up here in this bug report in the first place is because you're using the registry lookup instead of just using the existing windows environment vars that can be dynamically changed (a last resort which is not pretty, but at least possible without patching). I don't recall which package it was that used platformdirs, but it was trying to store huge models in my user profile.

My suggestion: PD_OVERRIDE_APPDATA, PD_OVERRIDE_LOCALAPPDATA, ... - clear override env vars that do not collide with existing vars, and by default the user vars APPDATA/LOCALAPPDATA/.. should be used instead of registry lookups,

[gaborbernat]

My suggestion: PD_OVERRIDE_APPDATA, PD_OVERRIDE_LOCALAPPDATA, ... - clear override env vars that do not collide with existing vars, and by default the user vars APPDATA/LOCALAPPDATA/.. should be used instead of registry lookups,

They might be prefixed by WIN_ because this is a Windows only problem, on unix XDG_ works fine 🤔 at which point makes me wonder if we can use XDG_ on Windows too, though not sure how well they map so might not be an issue.

[Hoernchen]

I was suggesting a longer prefix that is less generic than WIN_ to ensure that it does not collide with something else that picks the most obvious generic prefix + generic suffix ;)

[gaborbernat]

I meant that WIN_PD_OVERRIDE_APPDATA might be better to indicate is only usedOn Windows.

[Hoernchen]

Ah, yes, I guess that would work fine.