Binary string to Decimal integer converter

问题

I am trying to write a program that converts a 4-bit string representation of binary into a decimal (base 10) integer.

This is what I got so far, but after I type In the 4-bit binary (e.g. 1101) It just comes out with: '>>>'.

Here is the flow diagram I am following:

Here is my code:

def binaryToDenary():
    Answer = 0
    Column = 8
    Bit = int(input("Enter bit value: "))
    if Column >1:
        Answer = Answer + (Column * Bit)
        Column = Column/2
    elif Column <1:
        print("The decimal value is: " + Answer)


binaryToDenary()

What am I doing wrong? Any hints?

回答1:

It looks like you haven't implemented the loop:

def binaryToDenary():
    Answer = 0
    Column = 8
    while not Column < 1:
        Bit = int(input("Enter bit value: "))
        Answer = Answer + (Column * Bit)
        Column = Column/2
    print("The decimal value is: {}".format(Answer))

回答2:

You can use built-in methods or you can make your own function like so:

bintodec = lambda arg: sum(int(j) * 2**(len(arg) - i - 1) for i, j in enumerate(arg))

回答3:

Try this. This is a direct translation from the diagram. Note that in production code and real libraries, this is not a particularly useful function and is only useful as an examination exercise.

def integer_from_binary_input():
    answer = 0
    column = 8
    while True:
        bit_chars = raw_input("Enter bit value:")
        assert len(bit_chars) == 1
        assert bit_chars in "01"
        bit = int(bit_chars)
        answer = answer + column * bit
        column /= 2
        if column < 1:
            break
    print "Decimal value is: %d" % answer
    return answer

output = integer_from_binary_input()

来源：https://stackoverflow.com/questions/29578704/binary-string-to-decimal-integer-converter