Some simple Python float/int helpers

float_helpers.py

# Apache2 Licensed: https://www.apache.org/licenses/LICENSE-2.0

import struct

float2int = lambda f: struct.unpack('i', struct.pack('f', f))[0]
float2hex = lambda f: hex(float2int(f))
MASK_23B = (1 << 23) - 1

assert float2hex(1.0) == '0x3f800000'

def float2parts(f):
    x = float2int(f)
    s = x >> 31
    e = x >> 23 & 0xff
    f = x & MASK_23B
    return (s, e, f)

assert float2parts(1.0) == (0, 127, 0)

def parts2float(t):
    s, e, f = t
    assert s & 1 == s
    assert e & 0xff == e
    assert f & MASK_23B == f
    x = s << 31 | e << 23 | f
    return struct.unpack('f', struct.pack('i', x))[0]

for f in (1.0, 1.5, 2.0, 3.75, 0.0625):
    assert parts2float(float2parts(f)) == f, f