Unexpected Indent error in Python [duplicate]

Question

I have a simple piece of code that I'm not understanding where my error is coming from. The parser is barking at me with an Unexpected Indent on line 5 (the if statement). Does anyone see the problem here? I don't.

def gen_fibs():
    a, b = 0, 1
    while True:
        a, b = b, a + b
        if len(str(a)) == 1000:
            return a

Answer 1

If you just copy+pasted your code, then you used a tab on the line with the if statement. Python interprets a tab as 8 spaces and not 4. Don't ever use tabs with python¹ :)

^{1 Or at least don't ever use tabs and spaces mixed. It's highly advisable to use 4 spaces for consistency with the rest of the python universe.}

Answer 2

You're mixing tabs and spaces. Tabs are always considered the same as 8 spaces for the purposes of indenting. Run the script with python -tt to verify.