Signed decimal from a signed hex short in python

Question

I was wondering if theres any easy and fast way to obtain the decimal value of a signed hex in python.

What I do to check the value of a hex code is just open up python in terminal and type in the hex, it returns the decimal like this:

>>>0x0024
36
>>>0xcafe
51966

So I was wondering, is there any way that I could do that for signed short hex? for example 0xfffc should return -4

Answer 1

You can use the int classmethod from_bytes and provide it with the bytes:

>>> int.from_bytes(b'\xfc\xff', signed=True, byteorder='little')
-4

Answer 2

import ctypes

def hex2dec(v):
    return ctypes.c_int16(v).value

print hex2dec(0xfffc)
print hex2dec(0x0024)
print hex2dec(0xcafe)

Answer 3

If you can use NumPy numerical types you could use np.int16 type conversion

>>> import numpy as np
>>> np.int16(0x0024)
36
>>> np.int16(0xcafe)
-13570
>>> np.int16(0xfffc)
-4
>>> np.uint16(0xfffc)
65532
>>> np.uint16(0xcafe)
51966

Python Language specifies a unified representation for integer numbers, the numbers.Integral class, a subtype of numbers.Rational . In Python 3 there are no specific constraints on the range of this type. In Python 2 only the minimal range is specified, that is numbers.Integral should have at least the range of -2147483648 through 2147483647, that corresponds to the 32 bit representation.

NumPy implementation is closer to the machine architecture. To implement numeric operations efficiently it provides fixed width datatypes , such as int8 , int16 , int32 , and int64 .