dtype of np.random.choice differs with presence of p on windows

[jcrist]

The dtype of the output of np.random.choice with a scalar a is different if p is provided on windows:

>>> import numpy as np
>>> p = np.array([0.5, 0.5])
>>> np.random.choice(2, size=1).dtype
dtype('int32')
>>> np.random.choice(2, p=p, size=1).dtype
dtype('int64')
>>> np.__version__
1.13.1

I'd expect the output dtype to be consistent whether p is present or absent. Since the dtype of arange on win32 is int32, the int64 dtype output is probably the incorrect one.

[bashtage]

This difference occurs at

https://github.com/numpy/numpy/blob/master/numpy/random/mtrand/mtrand.pyx#L1155

since searchsorted returns int64 irrespective of platform.

[bashtage]

The return type for searchsorted is NPY_INTP here:

numpy/numpy/core/src/multiarray/item_selection.c

Line 1732 in c2372af

ret = (PyArrayObject *)PyArray_New(&PyArray_Type, PyArray_NDIM(ap2),

[bashtage]

@mattip This is fixed in Generator but not in RandomState. Should it be fixed in RandomState or left as it was in 1.16?

[mattip]

I guess this is a bug, and should be fixed, unless it breaks something else.