Emulate uint32_t in Python?

Question

I was trying to port a function from C to Python and to make it easy to debug, I'd prefer it performed the same CPU word-size limited operations so I could compare the intermediate results. In other words, I'd like something like:

a = UnsignedBoundedInt(32, 399999)
b = UnsignedBoundedInt(32, 399999)
print(a*b) # prints 1085410049 (159999200001 % 2**32)

What's the best way to achieve this so that all operations (including bitwise shifts) would work as in C?

Answer 1

You can try using ctypes.uint_32 to bound the results for you:

>>> import ctypes
>>> print ctypes.c_uint32(399999 * 399999).value
1085410049

Alternatively you can use numpy's data types:

>>> import numpy as np
>>> a = np.uint32(399999)
>>> b = np.uint32(399999)
>>> a * b
__main__:1: RuntimeWarning: overflow encountered in uint_scalars
1085410049