Python 中意外的缩进错误[重复]

我有一段简单的代码，我不明白我的错误来自哪里。解析器在第 5 行（if 语句）上用意外的缩进向我咆哮。有人看到这里的问题吗？我不。

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

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.}