Say I have the classic 4-byte signed integer, and I want something like
print hex(-1)
to give me something like
0xffffffff
In reality, the above gives me -0x1. I'm dawdling about in some lower level language, and python commandline is quick n easy.
So.. is there a way to do it?
This will do the trick:
>>> print(hex (-1 & 0xffffffff))
0xffffffff
or, a variant that always returns fixed size (there may well be a better way to do this):
>>> def hex3(n):
... return "0x%s"%("00000000%s"%(hex(n&0xffffffff)[2:-1]))[-8:]
...
>>> print hex3(-1)
0xffffffff
>>> print hex3(17)
0x00000011
Or, avoiding the hex() altogether, thanks to Ignacio and bobince:
def hex2(n):
return "0x%x"%(n&0xffffffff)
def hex3(n):
return "0x%s"%("00000000%x"%(n&0xffffffff))[-8:]
Try this function:
'%#4x' % (-1 & 0xffffffff)
Use
"0x{:04x}".format((int(my_num) & 0xFFFF), '04x')
where my_num is the required number.
Another way is to convert the signed integer to bytes first with int.to_bytes, then convert the bytes to a hex string with bytes.hex:
print((-1).to_bytes(4, signed=True).hex())
Output:
ffffffff
The reverse (hex string to signed integer): Hex string to signed int in Python
