Converting decimal numbers into floating point binary (Excess 64 format).

decToFloat.py

import math
# This solution assumes valid input in terms of type and range.
# Main returns the sign, exponent and mantissa in "Excess 64" format.
def main():
    value = float(input("Enter a number. "))
    sign = "0"
    
    if value < 0:
        sign = "1"
    
    value = abs(value)
    exponent = math.floor(math.log(value, 2))   
    mantissa = (value / (2 ** exponent)) - 1   
    mantissa = getBinary(mantissa, 0.5, 8)
    exponent = getBinary(exponent + 64, 2 ** 6, 7)
    
    return sign + exponent + mantissa


def getBinary(value, bitValue, bits):
    binary = ""
    for i in range(bits):
        if value >= bitValue:
          binary += "1"
          value -= bitValue
        else :
          binary += "0"
    
        bitValue /= 2
    
    return binary