生成器函数Python 2中的返回值

Question

I'm wondering how I can write a generator function that also has the option to return a value. In Python 2, you get the following error message if a generator function tries to return a value. SyntaxError: 'return' with argument inside generator

Is it possible to write a function where I specify if I want to receive a generator or not?

For example:

def f(generator=False):
    if generator:
        yield 3
    else:
        return 3

Answer 1

Mandatory reading: Understanding Generators in Python

Key information:

yield anywhere in a function makes it a generator.

Function is marked as generator when code is parsed. Therefore, it's impossible to toggle function behavior (generator / not generator) based on argument passed in runtime.