python convert a binary number to a decimal number
def binToDec(num):
    temp = str(num)
    arr = []
    final = []
    for i in temp:
        arr.append(i)
    arrNums = [str(x) for x in arr]
    arrNums.reverse()
    j = 0
    for i in range(0, len(arrNums)):
        factor = arrNums[i]*(2**j)
        j += 1
        final.append(factor)
    decimal = 0
    for i in range(0, len(final)):
        decimal += final[i]
    return decimal
if __name__ == "__main__":
	num = 101000
    print(binToDec(num)) # Expected Output : 40
