Python，“返回”外部函数错误

Question

I was writing this code in C++ and it kept giving me an answer that I didn't want so I thought I should write it in python, so when I did it gave me the error " * 'return' outside function ([Place on hard drive], line 7)". I searched it and found that it was to do with indentions, so I re-wrote that line of code but I still get this error. Also the program it's self is most likely wrong and I'm not asking for you to fix that but in theory it should work, also it is to convert decimal to binary as a number. Thanks in advance :).

Here's the code:

class gimmeANumber():
    while True:
        Number = raw_input("Please can you input a number from 0 to 255\n")
        if Number < 0 or 255 < number:
            print "Please enter a valid number\n"
        else:
            return Number

class decToBinary():
    Binary_Converter = 128
    i = 0
    Binary = 0
    while True:
        Number = gimmeANumber()
        ONumber = Number
        while (true):
            if (Number - Binary_Converter) >= 0:
                Number =- Binary_Converter
                Binary_Converter /= 2
                Binary += 10**7-i
            else:
                Binary_Converter /= 2
            i += 1
            if i == 8:
                break
    print "\nThe origanal number was " + str(ONumber) + " Now it is " + str(Binary) + " in Binary.\n"

Answer 1

尝试将class更改为def 。

Answer 2

You are telling Python that you are defining a class, because of the "class" keyword.

However, you instead should be defining a function, using "def".

There are a few other things you will need to fix to make this work. For example, gimmeANumber() should return a number, but it currently returns a string. The function should look like:

def gimmeANumber():
    while True:
        Number = raw_input("Please can you input a number from 0 to 255\n")
        Number = int(Number)
        if Number < 0 or 255 < Number:
            print "Please enter a valid number\n"
        else:
            return Number

Answer 3

Python has a built-in function to convert from decimal to binary ( bin() ).

number = int(raw_input('Give me a decimal integer, please: '))
print '%d in decimal is equivalent to %s in binary' % (number, bin(number)[2:])

And to convert from any base to decimal, you could do something like this:

number = int(raw_input('Give me a binary integer, please: '))
print '%d in binary is equivalent to %d in binary' % (number, int(number, 2))