How come I get a syntax error for using a ':' at the end of a for statement?

I'm writing my assignment in python, a simple binary calculation program and for some reason when I am executing the program, I get a syntax error, which I don't understand as I was told the ':' at the end of a for loop or while loop for that matter is essential, just like it would be for an if/elif/else statement.

The code for the whole section of that area of code is:

for m in range(binaryCountingVariable):
    countingDecimalVariable = m + 1
    countingBinaryVariable = ''
    while countingDecimalVariable != 0:
        countingDecimalRemainder = countingDecimalVariable % 2
        countingBinaryVariable = countingBinaryVariable + str(countingDecimalRemainder)
        countingDecimalVariable = countingDecimalVariable // 2
    print('Decimal:', i, '= Binary:', countingBinaryVariable[::-1], sep='')