[Tracker] Fix signature mismatch with NumPy/SciPy

[kmaehashi]

I found some functions have different signature than NumPy/SciPy (e.g. some arguments are keyword-only in NumPy but not in CuPy). We should check and fix them.

• cupy.arange
• cupy.argmax
• cupy.argmin
• cupy.array
• cupy.concatenate
• ...

Note: This list is not exhaustive (I'll try to complete the list but may take some time). If you find any functions with different signature leave a comment in this issue.

[andfoy]

NumPy mismatch

After comparing each signature (across all namespaces) between NumPy and CuPy by using this script https://gist.github.com/andfoy/5ad7e4c10fb82e851b5e359ae44d6eba, it is possible to conclude that the following functions' signatures present a mismatch between CuPy and their corresponding counterpart in NumPy.

Notes

1. The following functions require a manual inspection, since some of them are defined as ufuncs or builtin functions rather than proper functions, which prevent inspect.signature from working: cupy.arange, cupy.array, cupy.asanyarray, cupy.asarray, cupy.ascontiguousarray, cupy.asfortranarray, cupy.empty, cupy.frombuffer, cupy.fromfile, cupy.fromiter, cupy.fromstring, cupy.random.default_rng, cupy.random.ranf, cupy.random.sample, cupy.random.seed, cupy.zeros, numpy.fix, numpy.i0, numpy.sinc, numpy.size. The functions that present a mismatch are included on the table below.
2. The NumPy version used locally depends on the changes of https://github.com/numpy/numpy/pull/17818 and https://github.com/numpy/numpy/pull/21975

main namespace

Function	Observations
all	where: extra arg on numpy, is kwarg
alltrue	a: extra arg on cupy, is kwarg axis: extra arg on cupy, is kwarg out: extra arg on cupy, is kwarg keepdims: extra arg on cupy, is kwarg args: extra arg on numpy, is non-kwarg kwargs: extra arg on numpy, is non-kwarg
amax	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
amin	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
any	where: extra arg on numpy, is kwarg
arange	like: extra arg on numpy, is kwarg
argmax	dtype: extra arg on cupy, is kwarg
argmin	dtype: extra arg on cupy, is kwarg
argpartition	kind: extra arg on numpy, is kwarg order: extra arg on numpy, is kwarg
argsort	order: extra arg on numpy, is kwarg
array	like: extra arg on numpy, is kwarg
array2string	max_line_width: extra arg on numpy, is kwarg args: extra arg on cupy, is kwarg precision: extra arg on numpy, is kwarg kwargs: extra arg on cupy, is kwarg suppress_small: extra arg on numpy, is kwarg separator: extra arg on numpy, is kwarg prefix: extra arg on numpy, is kwarg style: extra arg on numpy, is kwarg formatter: extra arg on numpy, is kwarg threshold: extra arg on numpy, is kwarg edgeitems: extra arg on numpy, is kwarg sign: extra arg on numpy, is kwarg floatmode: extra arg on numpy, is kwarg suffix: extra arg on numpy, is kwarg legacy: extra arg on numpy, is kwarg
array_str	arr: extra arg on cupy, is kwarg a: extra arg on numpy, is non-kwarg
asanyarray	like: extra arg on numpy, is kwarg
asarray	like: extra arg on numpy, is kwarg
ascontiguousarray	like: extra arg on numpy, is kwarg
asfortranarray	like: extra arg on numpy, is kwarg
broadcast_arrays	subok: extra arg on numpy, is kwarg
broadcast_to	subok: extra arg on numpy, is kwarg
clip	kwargs: extra arg on numpy, is non-kwarg
concatenate	tup: extra arg on cupy, is kwarg arrays: extra arg on numpy, is non-kwarg
copy	subok: extra arg on numpy, is kwarg
corrcoef	a: extra arg on cupy, is kwarg x: extra arg on numpy, is non-kwarg
count_nonzero	keepdims: extra arg on numpy, is kwarg
cov	a: extra arg on cupy, is kwarg m: extra arg on numpy, is non-kwarg
cumproduct	a: extra arg on cupy, is kwarg axis: extra arg on cupy, is kwarg dtype: extra arg on cupy, is kwarg out: extra arg on cupy, is kwarg args: extra arg on numpy, is non-kwarg kwargs: extra arg on numpy, is non-kwarg
ediff1d	arr: extra arg on cupy, is kwarg ary: extra arg on numpy, is non-kwarg
einsum	out: extra arg on numpy, is kwarg optimize: extra arg on numpy, is kwarg
empty	like: extra arg on numpy, is kwarg
empty_like	a: extra arg on cupy, is kwarg prototype: extra arg on numpy, is non-kwarg
extract	arr: extra arg on numpy, is non-kwarg a: extra arg on cupy, is kwarg
eye	like: extra arg on numpy, is kwarg
fix	out: extra arg on numpy, is kwarg fix: should be introspectable,
flip	a: extra arg on cupy, is kwarg m: extra arg on numpy, is non-kwarg
fliplr	a: extra arg on cupy, is kwarg m: extra arg on numpy, is non-kwarg
flipud	a: extra arg on cupy, is kwarg m: extra arg on numpy, is non-kwarg
format_float_positional	precision: extra arg on numpy, is kwarg args: extra arg on cupy, is kwarg unique: extra arg on numpy, is kwarg kwargs: extra arg on cupy, is kwarg fractional: extra arg on numpy, is kwarg trim: extra arg on numpy, is kwarg sign: extra arg on numpy, is kwarg pad_left: extra arg on numpy, is kwarg pad_right: extra arg on numpy, is kwarg min_digits: extra arg on numpy, is kwarg
format_float_scientific	precision: extra arg on numpy, is kwarg args: extra arg on cupy, is kwarg unique: extra arg on numpy, is kwarg kwargs: extra arg on cupy, is kwarg trim: extra arg on numpy, is kwarg sign: extra arg on numpy, is kwarg pad_left: extra arg on numpy, is kwarg exp_digits: extra arg on numpy, is kwarg min_digits: extra arg on numpy, is kwarg
frombuffer	args: extra arg on cupy, does not declare the full argspec, is non-kwarg kwargs: extra arg on cupy, does not declare the full kwarg-spec, is kwarg
fromfile	args: extra arg on cupy, does not declare the full argspec, is non-kwarg kwargs: extra arg on cupy, does not declare the full kwarg-spec, is kwarg
fromfunction	args: extra arg on cupy, is kwarg function: extra arg on numpy, is non-kwarg shape: extra arg on numpy, is non-kwarg dtype: extra arg on numpy, is kwarg like: extra arg on numpy, is kwarg
fromiter	args: extra arg on cupy, does not declare the full argspec, is non-kwarg kwargs: extra arg on cupy, does not declare the full kwarg-spec, is kwarg
fromstring	args: extra arg on cupy, does not declare the full argspec, is non-kwarg kwargs: extra arg on cupy, does not declare the full kwarg-spec, is kwarg
full	like: extra arg on numpy, is kwarg
genfromtxt	args: extra arg on cupy, is kwarg kwargs: extra arg on cupy, is kwarg fname: extra arg on numpy, is non-kwarg dtype: extra arg on numpy, is kwarg comments: extra arg on numpy, is kwarg delimiter: extra arg on numpy, is kwarg skip_header: extra arg on numpy, is kwarg skip_footer: extra arg on numpy, is kwarg converters: extra arg on numpy, is kwarg missing_values: extra arg on numpy, is kwarg filling_values: extra arg on numpy, is kwarg usecols: extra arg on numpy, is kwarg names: extra arg on numpy, is kwarg excludelist: extra arg on numpy, is kwarg deletechars: extra arg on numpy, is kwarg replace_space: extra arg on numpy, is kwarg autostrip: extra arg on numpy, is kwarg case_sensitive: extra arg on numpy, is kwarg defaultfmt: extra arg on numpy, is kwarg unpack: extra arg on numpy, is kwarg usemask: extra arg on numpy, is kwarg loose: extra arg on numpy, is kwarg invalid_raise: extra arg on numpy, is kwarg max_rows: extra arg on numpy, is kwarg encoding: extra arg on numpy, is kwarg ndmin: extra arg on numpy, is kwarg like: extra arg on numpy, is kwarg
histogram	x: extra arg on cupy, is kwarg a: extra arg on numpy, is non-kwarg density: extra arg on numpy, is kwarg density: extra arg on cupy, is kwarg
histogram2d	density: extra arg on numpy, is kwarg density: extra arg on cupy, is kwarg
histogramdd	density: extra arg on numpy, is kwarg density: extra arg on cupy, is kwarg
hstack	dtype: extra arg on numpy, is kwarg casting: extra arg on numpy, is kwarg
identity	like: extra arg on numpy, is kwarg
in1d	kind: extra arg on numpy, is kwarg
indices	sparse: extra arg on numpy, is kwarg
intersect1d	arr1: extra arg on cupy, is kwarg arr2: extra arg on cupy, is kwarg ar1: extra arg on numpy, is non-kwarg ar2: extra arg on numpy, is non-kwarg
isin	kind: extra arg on numpy, is kwarg
lexsort	axis: extra arg on numpy, is kwarg
load	fix_imports: extra arg on numpy, is kwarg encoding: extra arg on numpy, is kwarg
loadtxt	args: extra arg on cupy, is kwarg kwargs: extra arg on cupy, is kwarg fname: extra arg on numpy, is non-kwarg dtype: extra arg on numpy, is kwarg comments: extra arg on numpy, is kwarg delimiter: extra arg on numpy, is kwarg converters: extra arg on numpy, is kwarg skiprows: extra arg on numpy, is kwarg usecols: extra arg on numpy, is kwarg unpack: extra arg on numpy, is kwarg ndmin: extra arg on numpy, is kwarg encoding: extra arg on numpy, is kwarg max_rows: extra arg on numpy, is kwarg quotechar: extra arg on numpy, is kwarg like: extra arg on numpy, is kwarg
logspace	axis: extra arg on numpy, is kwarg
max	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
mean	where: extra arg on numpy, is kwarg
meshgrid	copy: extra arg on numpy, is kwarg kwargs: extra arg on cupy, is kwarg sparse: extra arg on numpy, is kwarg indexing: extra arg on numpy, is kwarg
min	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
nanargmax	dtype: extra arg on cupy, is kwarg
nanargmin	dtype: extra arg on cupy, is kwarg
nanmax	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
nanmean	where: extra arg on numpy, is kwarg
nanmin	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
nanprod	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
nanstd	where: extra arg on numpy, is kwarg
nansum	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
nanvar	where: extra arg on numpy, is kwarg
ones	like: extra arg on numpy, is kwarg
partition	kind: extra arg on numpy, is kwarg order: extra arg on numpy, is kwarg
piecewise	args: extra arg on numpy, is non-kwarg kw: extra arg on numpy, is non-kwarg
prod	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
product	a: extra arg on cupy, is kwarg axis: extra arg on cupy, is kwarg dtype: extra arg on cupy, is kwarg out: extra arg on cupy, is kwarg keepdims: extra arg on cupy, is kwarg args: extra arg on numpy, is non-kwarg kwargs: extra arg on numpy, is non-kwarg
require	like: extra arg on numpy, is kwarg
rot90	a: extra arg on cupy, is kwarg m: extra arg on numpy, is non-kwarg
row_stack	dtype: extra arg on numpy, is kwarg casting: extra arg on numpy, is kwarg
save	fix_imports: extra arg on numpy, is kwarg
savetxt	fmt: extra arg on numpy, is kwarg args: extra arg on cupy, is kwarg delimiter: extra arg on numpy, is kwarg kwargs: extra arg on cupy, is kwarg newline: extra arg on numpy, is kwarg header: extra arg on numpy, is kwarg footer: extra arg on numpy, is kwarg comments: extra arg on numpy, is kwarg encoding: extra arg on numpy, is kwarg
show_config	_full: extra arg on cupy, is kwarg
sometrue	a: extra arg on cupy, is kwarg axis: extra arg on cupy, is kwarg out: extra arg on cupy, is kwarg keepdims: extra arg on cupy, is kwarg args: extra arg on numpy, is non-kwarg kwargs: extra arg on numpy, is non-kwarg
sort	order: extra arg on numpy, is kwarg
stack	tup: extra arg on cupy, is kwarg arrays: extra arg on numpy, is non-kwarg dtype: extra arg on numpy, is kwarg casting: extra arg on numpy, is kwarg
std	where: extra arg on numpy, is kwarg
sum	initial: extra arg on numpy, is kwarg where: extra arg on numpy, is kwarg
take	mode: extra arg on numpy, is kwarg
take_along_axis	a: extra arg on cupy, is kwarg arr: extra arg on numpy, is non-kwarg
tri	like: extra arg on numpy, is kwarg
union1d	arr1: extra arg on cupy, is kwarg arr2: extra arg on cupy, is kwarg ar1: extra arg on numpy, is non-kwarg ar2: extra arg on numpy, is non-kwarg
unpackbits	count: extra arg on numpy, is kwarg
unravel_index	shape: extra arg on numpy, is kwarg dims: extra arg on cupy, is kwarg
var	where: extra arg on numpy, is kwarg
vstack	dtype: extra arg on numpy, is kwarg casting: extra arg on numpy, is kwarg
zeros	like: extra arg on numpy, is kwarg

linalg namespace

Function	Observations
matrix_power	M: extra arg on cupy.linalg, is kwarg a: extra arg on numpy.linalg, is non-kwarg
matrix_rank	M: extra arg on cupy.linalg, is kwarg A: extra arg on numpy.linalg, is non-kwarg hermitian: extra arg on numpy.linalg, is kwarg
pinv	hermitian: extra arg on numpy.linalg, is kwarg
svd	hermitian: extra arg on numpy.linalg, is kwarg

testing namespace

Function	Observations
assert_allclose	equal_nan: extra arg on numpy.testing, is kwarg
assert_array_equal	strict: extra arg on numpy.testing, is kwarg strides_check: extra arg on cupy.testing, is kwarg
assert_warns	expected: extra arg on cupy.testing, is kwarg warning_class: extra arg on numpy.testing, is non-kwarg args: extra arg on numpy.testing, is non-kwarg kwargs: extra arg on numpy.testing, is non-kwarg

random namespace

Function	Observations
beta	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
binomial	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
chisquare	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
choice	size: same position, cupy.random is kwarg, numpy.random is non-kwarg replace: same position, cupy.random is kwarg, numpy.random is non-kwarg p: same position, cupy.random is kwarg, numpy.random is non-kwarg
dirichlet	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
exponential	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
f	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
gamma	scale: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
geometric	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
gumbel	loc: same position, cupy.random is kwarg, numpy.random is non-kwarg scale: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
hypergeometric	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
laplace	loc: same position, cupy.random is kwarg, numpy.random is non-kwarg scale: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
logistic	loc: same position, cupy.random is kwarg, numpy.random is non-kwarg scale: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
lognormal	mean: same position, cupy.random is kwarg, numpy.random is non-kwarg sigma: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
logseries	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
multinomial	size: same position, cupy.random is kwarg, numpy.random is non-kwarg
multivariate_normal	mean: extra arg on cupy.random, is kwarg cov: extra arg on cupy.random, is kwarg size: extra arg on cupy.random, is kwarg check_valid: extra arg on cupy.random, is kwarg tol: extra arg on cupy.random, is kwarg method: extra arg on cupy.random, is kwarg dtype: extra arg on cupy.random, is kwarg mean: extra arg on numpy.random, is non-kwarg cov: extra arg on numpy.random, is non-kwarg size: extra arg on numpy.random, is non-kwarg check_valid: extra arg on numpy.random, is non-kwarg tol: extra arg on numpy.random, is non-kwarg
negative_binomial	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
noncentral_chisquare	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
noncentral_f	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
normal	loc: same position, cupy.random is kwarg, numpy.random is non-kwarg scale: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
pareto	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
permutation	a: extra arg on cupy.random, is kwarg x: extra arg on numpy.random, is non-kwarg
poisson	lam: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
power	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
rand	size: extra arg on cupy.random, is kwarg kwarg: extra arg on cupy.random, is kwarg args: extra arg on numpy.random, is non-kwarg
randint	high: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: same position, cupy.random is kwarg, numpy.random is non-kwarg
randn	size: extra arg on cupy.random, is kwarg kwarg: extra arg on cupy.random, is kwarg args: extra arg on numpy.random, is non-kwarg
random	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
random_integers	high: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg
random_sample	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
rayleigh	scale: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
shuffle	a: extra arg on cupy.random, is kwarg x: extra arg on numpy.random, is non-kwarg
standard_cauchy	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
standard_exponential	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
standard_gamma	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
standard_normal	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
standard_t	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
triangular	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
uniform	low: same position, cupy.random is kwarg, numpy.random is non-kwarg high: same position, cupy.random is kwarg, numpy.random is non-kwarg size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
vonmises	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
wald	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
weibull	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg
zipf	size: same position, cupy.random is kwarg, numpy.random is non-kwarg dtype: extra arg on cupy.random, is kwarg

stride_tricks namespace

Function	Observations
as_strided	subok: extra arg on numpy.lib.stride_tricks, is kwarg writeable: extra arg on numpy.lib.stride_tricks, is kwarg

[andfoy]

SciPy comparison

The SciPy comparison is analog to the NumPy one, where functions and modules were compared using this script: https://gist.github.com/andfoy/a5acb14a60d7b46f0dd20fd6e0074d7d

Notes

1. The following functions cannot be compared directly since they are defined as ufunc or builtin_function: cupyx.scipy.fft.dct, cupyx.scipy.fft.dctn, cupyx.scipy.fft.dst, cupyx.scipy.fft.dstn, cupyx.scipy.fft.fft, cupyx.scipy.fft.fft2, cupyx.scipy.fft.fftn, cupyx.scipy.fft.fht, cupyx.scipy.fft.hfft, cupyx.scipy.fft.hfft2, cupyx.scipy.fft.hfftn, cupyx.scipy.fft.idct, cupyx.scipy.fft.idctn, cupyx.scipy.fft.idst, cupyx.scipy.fft.idstn, cupyx.scipy.fft.ifft, cupyx.scipy.fft.ifft2, cupyx.scipy.fft.ifftn, cupyx.scipy.fft.ifht, cupyx.scipy.fft.ihfft, cupyx.scipy.fft.ihfft2, cupyx.scipy.fft.ihfftn, cupyx.scipy.fft.irfft, cupyx.scipy.fft.irfft2, cupyx.scipy.fft.irfftn, cupyx.scipy.fft.next_fast_len, cupyx.scipy.fft.rfft, cupyx.scipy.fft.rfft2, cupyx.scipy.fft.rfftn, cupyx.scipy.special.round, scipy.special.sinc, scipy.special.zeta

sparse namespace

Function	Observations
spdiags	m: same position, cupyx.scipy.sparse is non-kwarg, scipy.sparse is kwarg n: same position, cupyx.scipy.sparse is non-kwarg, scipy.sparse is kwarg

fftpack namespace

Function	Observations
fft	plan: extra arg on cupyx.scipy.fftpack, is kwarg
fft2	plan: extra arg on cupyx.scipy.fftpack, is kwarg
fftn	plan: extra arg on cupyx.scipy.fftpack, is kwarg
ifft	plan: extra arg on cupyx.scipy.fftpack, is kwarg
ifft2	plan: extra arg on cupyx.scipy.fftpack, is kwarg
ifftn	plan: extra arg on cupyx.scipy.fftpack, is kwarg
rfft	plan: extra arg on cupyx.scipy.fftpack, is kwarg

[rgommers]

This is quite nice @andfoy. There may be an issue with your script for when the first argument of a function has a different name in cupy versus in numpy. Example from histogram:

x: extra arg on cupy, is kwarg
a: extra arg on numpy, is non-kwarg

As far as I can tell, they are both regular positional arguments. So the kwarg vs. non-kwarg thing is a bit of a red herring. Maybe you can figure out where it comes from and fix it?

Also, you may want to add a list of known exceptions that are okay. Example: density has a different default in numpy because of backwards compatibility reasons (None instead of False), but it's not desirable for cupy to match that - it is a regular boolean keyword in principle. Although in this particular case, the fix is to go remove normed from np.histogram - it has been deprecated for a few years.