SimpleBinaryToDecimal.py

# Binary-Conversion_lu.py
# With some error-handling form apaarfus

# Functions
def __isBinary(string):
    if string:
        for i in string:
            if not i.isnumeric():
                print('Error, contains non-numeric characters.')
                return False
            elif (int(i) < 0) or (int(i) > 1):
                print('Error, contains invalid digits.')
                return False
    else:
        print('Error, nothing was entered.')
        return False
    return True

def __binaryToDecimal(string):
        decimal = 0
        for i in string:
            print("Processing: \"" + i + "\"...")
            decimal = decimal*2 + int(digit)
        return decimal
    return -1

# Run
strInput = input('Enter a number: ')
if __isBinary(strInput):
    decimal = __binaryToDecimal(strInput)
    print("Binary:  " + strInput)
    print("Decimal: " + str(decimal))