This was opened on the Numba issue tracker: numba/numba#4374

It seems like NumPy has a function alen() which does AFAICT not appear in the documentation but evidently exists https://github.com/numpy/numpy/blob/master/numpy/core/fromnumeric.py#L2758. Git blame suggests it appeared in and hasn't changed since ~2005. I cannot see any places in the NumPy code base where this is used apart from its own unit tests. It also has some perhaps unusual behaviour, e.g.:

import numpy as np
np.alen(np) # <--- yes this works !

I'm not sure what the use case for this function would be?
Perhaps it {c,sh}ould be considered for deprecation?