In [1]: import numpy as np, inspect

In [2]: inspect.signature(np.random.poisson)
Out[2]: <Signature (lam, size)>

In [1]: import numpy as np, inspect

In [2]: inspect.signature(np.random.poisson)
Out[2]: <Signature (lam=1.0, size=None)>

In [1]: import numpy as np, inspect

In [2]: from unittest import mock

In [3]: m = mock.patch.object(np.random, "poisson", autospec=True).start()

In [4]: np.random.poisson(lam=0.5)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[4], line 1
----> 1 np.random.poisson(lam=0.5)

File <string>:2, in poisson(*args, **kwargs)

File ~/.pyenv/versions/3.11.0/lib/python3.11/unittest/mock.py:185, in _set_signature.<locals>.checksig(*args, **kwargs)
    184 def checksig(*args, **kwargs):
--> 185     sig.bind(*args, **kwargs)

File ~/.pyenv/versions/3.11.0/lib/python3.11/inspect.py:3204, in Signature.bind(self, *args, **kwargs)
   3199 def bind(self, /, *args, **kwargs):
   3200     """Get a BoundArguments object, that maps the passed `args`
   3201     and `kwargs` to the function's signature.  Raises `TypeError`
   3202     if the passed arguments can not be bound.
   3203     """
-> 3204     return self._bind(args, kwargs)

File ~/.pyenv/versions/3.11.0/lib/python3.11/inspect.py:3174, in Signature._bind(self, args, kwargs, partial)
   3167 except KeyError:
   3168     # We have no value for this parameter.  It's fine though,
   3169     # if it has a default value, or it is an '*args'-like
   3170     # parameter, left alone by the processing of positional
   3171     # arguments.
   3172     if (not partial and param.kind != _VAR_POSITIONAL and
   3173                                         param.default is _empty):
-> 3174         raise TypeError('missing a required argument: {arg!r}'. \
   3175                         format(arg=param_name)) from None
   3177 else:
   3178     if param.kind == _POSITIONAL_ONLY:
   3179         # This should never happen in case of a properly built
   3180         # Signature object (but let's have this check here
   3181         # to ensure correct behaviour just in case)

TypeError: missing a required argument: 'size'```

In [1]: import sys, numpy; print(numpy.__version__); print(sys.version)
1.26.0b1
3.11.0 (main, Dec  1 2022, 19:33:09) [GCC 12.2.0]

In [2]: print(numpy.show_runtime())
WARNING: `threadpoolctl` not found in system! Install it by `pip install threadpoolctl`. Once installed, try `np.show_runtime` again for more detailed build information
[{'numpy_version': '1.26.0b1',
  'python': '3.11.0 (main, Dec  1 2022, 19:33:09) [GCC 12.2.0]',
  'uname': uname_result(system='Linux', node='<redacted>', release='6.3.11-redacted-amd64', version='#1 SMP PREEMPT_DYNAMIC Debian 6.3.11-redacted (2023-07-18)', machine='x86_64')},
 {'simd_extensions': {'baseline': ['SSE', 'SSE2', 'SSE3'],
                      'found': ['SSSE3',
                                'SSE41',
                                'POPCNT',
                                'SSE42',
                                'AVX',
                                'F16C',
                                'FMA3',
                                'AVX2'],
                      'not_found': ['AVX512F',
                                    'AVX512CD',
                                    'AVX512_KNL',
                                    'AVX512_KNM',
                                    'AVX512_SKX',
                                    'AVX512_CLX',
                                    'AVX512_CNL',
                                    'AVX512_ICL',
                                    'AVX512_SPR']}}]
None