Convert hex to float

Question

How to convert the following hex string to float (single precision 32-bit) in Python?

\"41973333\" -> 1.88999996185302734375E1

\"41995C29\" -> 1.91700         


        

Answer 1

Slice up the hex strings into 2-character chunks (bytes), make each chunk into the right byte with int formatting, struct.unpack when done. I.e.:

import struct 

testcases = {
"41973333": 1.88999996185302734375E1,
"41995C29": 1.91700000762939453125E1,
"470FC614": 3.6806078125E4,
}

def hex2float(s):
    bins = ''.join(chr(int(s[x:x+2], 16)) for x in range(0, len(s), 2))
    return struct.unpack('>f', bins)[0]

for s in testcases:
  print hex2float(s), testcases[s]

emitting, as desired:

18.8999996185 18.8999996185
19.1700000763 19.1700000763
36806.078125 36806.078125