numpy.alen() called by numpy_func, but alen() is deprecated

[sharonzitara]

pint/pint/facets/numpy/numpy_func.py

Line 897 in 37a61ed

"alen",

In the latest pre-release of NumPy (https://github.com/numpy/numpy/releases/tag/v1.23.0rc2), alen has been removed due to its deprecation expiring. Pint's numpy_func is still calling alen here.

NumPy 1.18.0 release notes indicate that len should be used instead.

[wenx-z]

Would definitely appreciate an update here! This is breaking our production pipelines.

[jules-ch]

@wenx-z can you describe the error you encounter ?
it should work even if the numpy version have removed it.

[wenx-z]

from pint import UnitRegistry
  File ".../env/lib/python3.8/site-packages/pint/__init__.py", line 28, in <module>
    from .measurement import Measurement
  File ".../env/lib/python3.8/site-packages/pint/measurement.py", line 12, in <module>
    from .quantity import Quantity
  File ".../env/lib/python3.8/site-packages/pint/quantity.py", line 47, in <module>
    from .numpy_func import (
  File ".../env/lib/python3.8/site-packages/pint/numpy_func.py", line 860, in <module>
    implement_func("function", func_str, input_units=None, output_unit=None)
  File ".../env/lib/python3.8/site-packages/pint/numpy_func.py", line 263, in implement_func
    func = getattr(np, func_str_split[0])
  File ".../env/lib/python3.8/site-packages/numpy/__init__.py", line 311, in __getattr__
    raise AttributeError("module {!r} has no attribute "
AttributeError: module 'numpy' has no attribute 'alen'

[keewis]

well, that makes sense to me: __array_function__ registers by function object, not by name, so we need to access the attribute. This is a easy fix, though: remove a single line plus a test (if that exists).

Feel free to send in a PR, @wenx-z (no pressure, though).