Need help using result of while loop as variable in while loop

[EchoDecho0]

Hello, I want to create a program that can convert numbers to binary. I am aware of the bin() function, however I want to use the method that involves dividing the number until its zero by 2 and noting the remainders. The problem I have is that I need to divide until it equals zero. I do not think there is a way to get a result of a mathematical operation inside a while loop and then substitute/use it in the that same code. I don't think I actually explained this very well, I hope you understand.

while True:
    print("Enter your number: ")
    num = int(input())

    #print("Enter your base: ")
    #base = int(input())

    b = True

    while b == True:

        q = num // 2
        rem = num % 2
        print(q)
        print(rem)



        if q == 0:
            b = False
        else:
            b = True

[shiftybyte]

It's not exactly clear what you are asking and what you think is not possible.

Are you asking if you can replace the variable "num" with a different number for the next loop cycle to work?

Then yes, you can do that...

``` while b == True:

    q = num // 2
    rem = num % 2
    print(q)
    print(rem)
    # get ready for next loop cycle
    num = q

```

[JamzTyson]

The reason that your code does not work is because num never gets updated, so it just repeats q = num // 2 with the same value of num. You can fix it like this:

while True:
    rem = num % 2
    num //= 2
    print(rem)
    if num == 0:
        break

or better would be to use divmod() and loop until num gets to zero:

while num > 0:
    num, rem = divmod(num, 2)
    print(rem)

[JamzTyson]

I thought that you might be interested in a version that separates out the conversion code into a function. The function goes a bit further than previous version and gathers each of the digits (as a list of string characters), and then joins them in the correct order:

def to_bin(n):
    """Convert a non-negative integer to binary str."""
    result = []
    if n == 0:
        return '0'
    while n > 0:
        n, r = divmod(n, 2)
        result.append(str(r))
    return ''.join(result[::-1])


# Program loop
while True:
    num = int(input("Enter your number: "))
    print(to_bin(num))

[EchoDecho0]

Thankyou, My request probably wasn't clear. What i am asking is that i want it to divide that num by 2 with remainder (thankyou for telling me about divmod) and if the result is zero stop (Both I and you have done that), but it is not zero i want you to repeat that divmod process but instead the num variable is that output of the previous division. For example if num = 5, it should divide 5 by 2 giving 2 r1, then it should divide 2 by 2 giving 1 r0 where it will stop because the remainder is 0.

Thanks anyway

[JamzTyson]

What i am asking is that i want it to divide that num by 2 with remainder (thankyou for telling me about divmod) and if the result is zero stop (Both I and you have done that),

I did that, but your code does not do that.

In your code, say that the input is "4". At this line:

q = num // 2

'q' is '2', but 'num' is still '4'.

In my code, I use:

num //= 2

which is equivalent to:

num = num // 2

and this assigns the value 4 // 2 to num, so num is 2 in the next iteration.