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[Bug]: incompatible (wrt CPython 3.12) signatures for some integer math functions and int's methods #998
Description
Describe the bug
Python 3.12.13 (tags/v3.12.13:3bb231a6a5d, May 14 2026, 11:06:30) [GCC 14.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import math, inspect
>>> for fn in ["comb", "factorial", "gcd", "isqrt", "lcm", "perm"]:
... f = getattr(math, fn)
... print(f, inspect.signature(f))
...
<built-in function comb> (n, k, /)
<built-in function factorial> (n, /)
<built-in function gcd> (*integers)
<built-in function isqrt> (n, /)
<built-in function lcm> (*integers)
<built-in function perm> (n, k=None, /)
>>> for meth in dir(int):
... m = getattr(int, meth)
... if meth.startswith("_") or not callable(m):
... continue
... try:
... print(meth, inspect.signature(m))
... except ValueError:
... pass
...
as_integer_ratio (self, /)
bit_count (self, /)
bit_length (self, /)
from_bytes (bytes, byteorder='big', *, signed=False)
is_integer (self, /)
to_bytes (self, /, length=1, byteorder='big', *, signed=False)In the GraalPy instead:
Python 3.12.8 (Tue Jun 23 15:17:16 UTC 2026)
[Graal, GraalVM CE, Java 25.0.3 (amd64)] on 'linux'
Type "help", "copyright", "credits" or "license" for more information.
>>> import math, inspect
>>> for fn in ["comb", "factorial", "gcd", "isqrt", "lcm", "perm"]:
... f = getattr(math, fn)
... print(f, inspect.signature(f))
...
<built-in function comb> (a, b, /)
<built-in function factorial> (a, /)
<built-in function gcd> (*args, **kwargs)
<built-in function isqrt> (a, /)
<built-in function lcm> (*args, **kwargs)
<built-in function perm> (n, k, /)
>>> for meth in dir(int):
... m = getattr(int, meth)
... if meth.startswith("_") or not callable(m):
... continue
... try:
... print(meth, inspect.signature(m))
... except ValueError:
... pass
...
as_integer_ratio (self, /)
bit_count (self, /)
bit_length (self, /)
conjugate (self, /)
from_bytes (bytes, byteorder, /, *, signed)
is_integer (self, /)
to_bytes (self, length, byteorder, /, *, signed)As you can see, all present function signatures from the math module are different. Of course, most functions have positional-only arguments and naming differences aren't significant. But differences for gcd, lcm and perm - are. Same true for to_bytes/from_bytes methods: they lack default values and incorrectly specify positional-only arguments.
Though, I would appreciate if signatures will be fully compatible, including naming of positional-only parameters. The reason is that such naming is used in the Python prose docs, e.g. https://docs.python.org/3.12/library/math.html#math.comb. The GraalPy has no documentation like this for the stdlib.
Operating system
Linux
CPU architecture
x86_64
GraalPy version
25.1.3
JDK version
No response
Context configuration
No response
Steps to reproduce
See bug description.
Expected behavior
Match CPython.
Stack trace
Additional context
No response
Activity
skirpichev commentedon Nov 4, 2026
It seems that some cases could be easily solved by attached patch.
Details
The rest requires better support for signatures of builtins:
*args(and**kwargs)msimacek commentedon Nov 4, 2026
Thanks. Renaming the
argsandkwargsseems like a straighforward addition to the current system, but the default parameter values will be tricky, because we can't have python objects in the annotations that we use to declare those. We would need some way to map string values to python objects which will be awkward for things like module constants. And we would need to integrate that with the clinic system we have for argument conversions. I'll need to think about it more.