pep562

1.1 verified Fri May 01 auth: no python deprecated

Backport of PEP 562 (customizing module __getattr__ and __dir__) for Python 2.7, 3.5, and 3.6. Current version 1.1, last updated in 2019. Low release cadence.

pip install pep562

Common errors

error ImportError: No module named pep562 ↓

cause The library is not installed.

fix

Run pip install pep562 and ensure the environment is activated.

error AttributeError: module 'your_module' has no attribute '__getattr__' ↓

cause `patch_module` was not called, or the function is not defined as a module-level __getattr__.

fix

Call pep562.patch_module(__name__) and define a top-level function named __getattr__.

Warnings

deprecated PEP 562 is natively supported in Python 3.7+. This backport is only needed for Python <= 3.6. ↓

fix Remove dependency and conditional imports when targeting Python >= 3.7.

gotcha The library must be imported and `patch_module` called before any other code that relies on __getattr__ or __dir__. ↓

fix Ensure `import pep562; pep562.patch_module(__name__)` is executed early, preferably at the top of the module.

Imports

pep562
```
import pep562
```
PEP 562 is natively supported in Python 3.7+. This library is only needed for older versions.

Quickstart

Patches the current module to support PEP 562 on Python < 3.7.

import sys

if sys.version_info < (3, 7):
    import pep562
    pep562.patch_module(__name__)

# Define module-level __getattr__ and __dir__
def __getattr__(name):
    if name == 'missing':
        return 'default'
    raise AttributeError(f"module {__name__!r} has no attribute {name!r}")

def __dir__():
    return ['existing']