BUG: Missing signatures for ufuncs #30095
Description
Describe the issue:
Numpy ufuncs do not have valid signatures.
Reproduce the code example:
import numpy as np
import inspect
inspect.signature(np.ufunc.accumulate)
inspect.signature(np.ufunc.at)
inspect.signature(np.ufunc.outer)
inspect.signature(np.ufunc.reduce)
inspect.signature(np.ufunc.reduceat)
inspect.signature(np.ufunc.resolve_dtypes)Error message:
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
Cell In[28], line 1
----> 1 inspect.signature(np.ufunc.accumulate)
File ~/miniconda3/lib/python3.10/inspect.py:3254, in signature(obj, follow_wrapped, globals, locals, eval_str)
3252 def signature(obj, *, follow_wrapped=True, globals=None, locals=None, eval_str=False):
3253 """Get a signature object for the passed callable."""
-> 3254 return Signature.from_callable(obj, follow_wrapped=follow_wrapped,
3255 globals=globals, locals=locals, eval_str=eval_str)
File ~/miniconda3/lib/python3.10/inspect.py:3002, in Signature.from_callable(cls, obj, follow_wrapped, globals, locals, eval_str)
2998 @classmethod
2999 def from_callable(cls, obj, *,
3000 follow_wrapped=True, globals=None, locals=None, eval_str=False):
3001 """Constructs Signature for the given callable object."""
-> 3002 return _signature_from_callable(obj, sigcls=cls,
3003 follow_wrapper_chains=follow_wrapped,
3004 globals=globals, locals=locals, eval_str=eval_str)
File ~/miniconda3/lib/python3.10/inspect.py:2468, in _signature_from_callable(obj, follow_wrapper_chains, skip_bound_arg, globals, locals, eval_str, sigcls)
2463 return _signature_from_function(sigcls, obj,
2464 skip_bound_arg=skip_bound_arg,
2465 globals=globals, locals=locals, eval_str=eval_str)
2467 if _signature_is_builtin(obj):
-> 2468 return _signature_from_builtin(sigcls, obj,
2469 skip_bound_arg=skip_bound_arg)
2471 if isinstance(obj, functools.partial):
2472 wrapped_sig = _get_signature_of(obj.func)
File ~/miniconda3/lib/python3.10/inspect.py:2275, in _signature_from_builtin(cls, func, skip_bound_arg)
2273 s = getattr(func, "__text_signature__", None)
2274 if not s:
-> 2275 raise ValueError("no signature found for builtin {!r}".format(func))
2277 return _signature_fromstr(cls, func, s, skip_bound_arg)
ValueError: no signature found for builtin <method 'accumulate' of 'numpy.ufunc' objects>Python and NumPy Versions:
2.2.6
3.10.12 | packaged by conda-forge | (main, Jun 23 2023, 22:41:52) [Clang 15.0.7 ]
Runtime Environment:
No response
Context for the issue:
In Dask we fixed a bug where dask.array.cumprod wasn't passing the dtype down to the underlying function calls. To do this we inspect the funcs passed in for a dtype kwarg, and if set to use a partial to pass the dtype on.
When used with numpy ufuncs we are now seeing exceptions because the methods do not have valid signatures so we can't check if they have a dtype kwarg. See dask/dask#12117
We could special case this in Dask as all ufuncs have a dtype kwarg, but it would be better if we could inspect them to discover this at runtime.
#23993 is related