2s Compliment Calculator

Example:

Code:

def binaryToDecimal(val: str) -> int: 
    return int(val, 2) 

def decimalToBinary(n: int) -> str:
    return bin(n).replace("0b", "")

def fillBinaryZero(binary: str, bitLenght: int) -> str:
    offset = bitLenght - len(binary) 
    toReturn = binary[::-1]
    for i in range(0,offset):
        toReturn += '0'
    return toReturn[::-1]

def twosComplement(binary: str, isNegative: bool) -> str:
    # 1. Convert the positive value into 7-bit binary
    # remove MSB
    reversedStrBinary = binary[1:][::-1]
    print('removesignbit: ', reversedStrBinary[::-1])
    
    # Invert
	# 2. Invert the digits (12 -> 02, 02 -> 12) 
    invertedStrBinary = ""
    for i in range(0,len(reversedStrBinary)):
        invertedStrBinary += '0' if reversedStrBinary[i] == '1' else '1'
    print('\n-----------------------------------')
    print('2. Inverting the bit')
    print('invert binary: ', invertedStrBinary[::-1])
    
    # add 1s
    # 3. Add 1s complement 
    if '1' in invertedStrBinary:
        invertedStrBinary = fillBinaryZero(decimalToBinary(binaryToDecimal(invertedStrBinary[::-1]) + 1), len(reversedStrBinary))
    else:
        invertedStrBinary = invertedStrBinary[0:-1] + '1'
    
    print('\n-----------------------------------')
    print('3. Add 1 complement')
    print('+1 Binary:     ', invertedStrBinary)
    
    # 4. Add 1s sign bit to negative 
    print('\n-----------------------------------')
    print('4. Apply negative sign to the MSB')
    return '1' + str(invertedStrBinary)

def main() -> None:
    """ Description """
    
    while True:
        userInput = input("Enter decimal value: ")
        
        # Without any input, break the loop
        if len(userInput) == 0:
            print("End of program.")
            break
        
        try:
            while True:
                bitLenght = int(input("Enter Total Bit Lenght (including sign bit): ")) 
                break
        except:
            print("Invalid bit lenght")
        decimal = int(userInput)
        
        if bitLenght - len(userInput) < 0:
            print('Invalid Bit Lenght')
        else: 
            # check if negative
            if decimal < 0:
                isNegative = True
                decimal = decimal * -1
            else: 
                isNegative = False
            
            binary = fillBinaryZero(str(decimalToBinary(decimal)), bitLenght)
            print('\n-----------------------------------')
            print('1. Convert to Binary\nIf negative decmial, change to positive decimal into 7-bit binary first')
            print(f'Decimal: {userInput:>14}\n+ve Decimal: {decimal:>10}\nBinary: {binary:>15}')
            finalBinary = twosComplement(binary,isNegative) if isNegative else binary
            print('2scomplement: ', finalBinary)
            print('\n-----------------------------------')
            print(f'Answer: {userInput} = {finalBinary}')
            print('-----------------------------------\n')
            
                
if __name__ == "__main__":
    main()