AttributeError: module 'numpy' has no attribute 'alen'

[chojeonga]

What went wrong?

I got AttributeError

from metpy.interpolate import (interpolate_to_grid, remove_nan_observations, remove_repeat_coordinates)

AttributeError: module 'numpy' has no attribute 'alen'

Operating System

MacOS

Version

metpy1.6

Python Version

python 3.10.9

Code to Reproduce

from metpy.interpolate import (interpolate_to_grid, remove_nan_observations, remove_repeat_coordinates)

Errors, Traceback, and Logs

No response

[akrherz]

How did you install MetPy? Can you please provide the full python traceback for the AttributeError?

[chojeonga]

conda install -c conda-forge metpy

Traceback (most recent call last):
  File "/Users/eprl/workplace/Prediction/code/plot/4_interpolation.py", line 10, in <module>
    from metpy.interpolate import (interpolate_to_grid, remove_nan_observations,
  File "/Users/eprl/anaconda3/lib/python3.10/site-packages/metpy/__init__.py", line 35, in <module>
    from .xarray import *  # noqa: F401, F403
  File "/Users/eprl/anaconda3/lib/python3.10/site-packages/metpy/xarray.py", line 28, in <module>
    from .units import DimensionalityError, UndefinedUnitError, units
  File "/Users/eprl/anaconda3/lib/python3.10/site-packages/metpy/units.py", line 22, in <module>
    import pint
  File "/Users/eprl/anaconda3/lib/python3.10/site-packages/pint/__init__.py", line 28, in <module>
    from .measurement import Measurement
  File "/Users/eprl/anaconda3/lib/python3.10/site-packages/pint/measurement.py", line 12, in <module>
    from .quantity import Quantity
  File "/Users/eprl/anaconda3/lib/python3.10/site-packages/pint/quantity.py", line 47, in <module>
    from .numpy_func import (
  File "/Users/eprl/anaconda3/lib/python3.10/site-packages/pint/numpy_func.py", line 860, in <module>
    implement_func("function", func_str, input_units=None, output_unit=None)
  File "/Users/eprl/anaconda3/lib/python3.10/site-packages/pint/numpy_func.py", line 263, in implement_func
    func = getattr(np, func_str_split[0])
  File "/Users/eprl/anaconda3/lib/python3.10/site-packages/numpy/__init__.py", line 311, in __getattr__
    raise AttributeError("module {!r} has no attribute "
AttributeError: module 'numpy' has no attribute 'alen'

[akrherz]

sounds like an incompatable version of numpy, which version do you have installed? see hgrecco/pint#1532

[dopplershift]

Yes, the output of conda list numpy and conda list pint would be helpful.

[chojeonga]

Which one should I delete?

Name Version Build Channel

numpy 1.23.4 py310hb93e574_0
numpy-base 1.23.4 py310haf87e8b_0
numpydoc 1.5.0 py310hca03da5_0

Name Version Build Channel

pint 0.11 py_1 conda-forge/label/cf202003

[dopplershift]

pint 0.11 is way too old, and I'm not even sure how that's installed given that on conda-forge, MetPy 1.6 lists pint >= 0.17 as one of its requirements.

Regardless, I think your solution should be: conda update pint, which should install pint 0.23.