Maximum and minimum value of C types integers from

I'm looking for a way to get (using Python) the maximum and minimum values of C types integers (ie uint8, int8, uint16, int16, uint32, int32, uint64, int64...) from Python.

I was expecting to find this in ctypes module

In [1]: import ctypes
In [2]: ctypes.c_uint8(256)
Out[2]: c_ubyte(0)
In [3]: ctypes.c_uint8(-1)
Out[3]: c_ubyte(255)

but I couldn't find it.

Julia have great feature for this:

julia> typemax(UInt8)
0xff

julia> typemin(UInt8)
0x00

julia> typemin(Int8)
-128

julia> typemax(Int8)
127

I'm pretty sure Python have something quite similar.

Ideally I'm even looking for a way to ensure that a given Python integer (which is said to be unbounded) can be converted safely in a C type integer of a given size. When number is not in expected interval, it should raise an exception.

Currently overflow doesn't raise exception:

In [4]: ctypes.c_uint8(256)
Out[4]: c_ubyte(0)

I saw this SO post Maximum and Minimum values for ints but it's a bit different as author is looking for min/max value of a Python integer... not a C integer (from Python)

I also noticed Detecting C types limits ("limits.h") in python? but, even if it's quite related, it doesn't really answer my question.

According to: [Python 3.Docs]: Numeric Types - int, float, complex:

Integers have unlimited precision.

Translated to code:

>>> i = 10 ** 100
>>> i
10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
>>> len(str(i))
101
>>> i.bit_length()
333

On the other hand, each C type has a fixed size (depending on platform / architecture), as clearly shown in [CppReference]: Fundamental types.

Since [Python 3]: ctypes - A foreign function library for Python doesn't mention anything about types limits (note that there is some stuff not documented here), let's find that out manually.

code.py:

#!/usr/bin/env python3

import sys
from ctypes import c_int8, c_uint8, c_byte, c_ubyte, c_int16, c_uint16, \
    c_int32, c_uint32, c_int, c_uint, c_long, c_ulong, c_longlong, c_ulonglong, \
    c_int64, c_uint64, \
    sizeof


def limits(c_int_type):
    signed = c_int_type(-1).value < c_int_type(0).value
    bit_size = sizeof(c_int_type) * 8
    signed_limit = 2 ** (bit_size - 1)
    return (-signed_limit, signed_limit - 1) if signed else (0, 2 * signed_limit - 1)


def main():
    test_types = [
        c_int8,
        c_uint8,
        c_byte,
        c_ubyte,
        c_int16,
        c_uint16,
        c_int32,
        c_uint32,
        c_int,
        c_uint,
        c_long,
        c_ulong,
        c_longlong,
        c_ulonglong,
        c_int64,
        c_uint64
    ]
    for test_type in test_types:
        print("{:s} limits: ({:d}, {:d})".format(test_type.__name__, *limits(test_type)))


if __name__ == "__main__":
    print("Python {:s} on {:s}\n".format(sys.version, sys.platform))
    main()

Notes:

Code relies on the fact that for a certain integral type, its interval (and limits are interval's endpoints) is:
- signed _{(2's complement)}: [-(2 ^{bit_size - 1}), 2 ^{bit_size - 1} - 1]
- unsigned: [0, 2 ^bit_size - 1]
To check the a type's signum, use -1 (which will automatically be converted to the upper limit (due to wrap around arithmetic) by unsigned types)
There are lots of duplicates the output (below), because some types are simply "aliases" to others
The rest of your task (creating a function that compares a Python int to the ctypes type limits, and raises an exception if it isn't) is trivial, so I didn't implement it
This is for demonstrating purpose only, so I didn't do any argument check

Output:

(py35x64_test) e:\Work\Dev\StackOverflow\q052475749>"e:\Work\Dev\VEnvs\py35x64_test\Scripts\python.exe" code.py
Python 3.5.4 (v3.5.4:3f56838, Aug  8 2017, 02:17:05) [MSC v.1900 64 bit (AMD64)] on win32

c_byte limits: (-128, 127)
c_ubyte limits: (0, 255)
c_byte limits: (-128, 127)
c_ubyte limits: (0, 255)
c_short limits: (-32768, 32767)
c_ushort limits: (0, 65535)
c_long limits: (-2147483648, 2147483647)
c_ulong limits: (0, 4294967295)
c_long limits: (-2147483648, 2147483647)
c_ulong limits: (0, 4294967295)
c_long limits: (-2147483648, 2147483647)
c_ulong limits: (0, 4294967295)
c_longlong limits: (-9223372036854775808, 9223372036854775807)
c_ulonglong limits: (0, 18446744073709551615)
c_longlong limits: (-9223372036854775808, 9223372036854775807)
c_ulonglong limits: (0, 18446744073709551615)