Unhexing Float Numbers in Python

Sometimes it may be necessary to convert a hexadecimal representation of a float number to the actual float value in Python. This can be achieved using the struct module.

Here is an example code snippet that demonstrates how to unhex a float number in Python:

import struct

def unhex_float(hex_str):
    # Convert hex string to bytes object
    hex_bytes = bytes.fromhex(hex_str)
    
    # Determine the byte-order of the system    
    byte_order = '<' if struct.pack('h', 1) == b'\x01\x00' else '>'
    
    # Pack bytes as a 32-bit float in the appropriate byte-order
    float_bytes = struct.pack(byte_order + 'f', *struct.unpack('>f', hex_bytes))
    
    # Unpack the bytes as a 32-bit float in native byte-order
    return struct.unpack('f', float_bytes)[0]

The above function takes a hexadecimal string as input and returns the corresponding float value. It works by first converting the hex string to a bytes object and then packing it as a 32-bit float in the appropriate byte-order based on the system's architecture. It then unpacks this packed bytes object as a 32-bit float in native byte-order and returns the float value.

Here is an example usage of the above function:

>>> unhex_float('3f800000')
1.0
>>> unhex_float('c0490fdb')
-30.56999969482422
>>> unhex_float('41d748b1')
28.029998779296875

In the example above, we pass in different hex strings representing float values, and the function returns the actual float values.

In conclusion, unhexing float numbers in Python is a relatively easy task that can be accomplished using the struct module. The above code snippet provides a simple function to convert a hex string to a float value in Python.