Is there a Python function that checks if a generator is started?

Question

I try to define a generator function mycount() that can be reset with the generator function send(0) as in the example below. Everything works fine

Answer 1

Here's a complete implementation Python2 compatible routine, getgeneratorstate(gtor), with test code.

import unittest
import enum

class GtorState(enum.Enum):
    GEN_RUNNING ='GEN_RUNNING'
    GEN_CLOSED ='GEN_CLOSED'
    GEN_CREATED ='GEN_CREATED'
    GEN_SUSPENDED ='GEN_SUSPENDED'

    @staticmethod
    def getgeneratorstate(gtor):
        if gtor.gi_running:
            return GtorState.GEN_RUNNING

        if gtor.gi_frame is None:
            return GtorState.GEN_CLOSED

        if gtor.gi_frame.f_lasti == -1:
            return GtorState.GEN_CREATED

        return GtorState.GEN_SUSPENDED
    #end-def

def coro000():
    """ a coroutine that does little 

    """ 
    print('-> coroutine started')
    x =yield
    print('-> coroutine received ', x)


class Test_Coro(unittest.TestCase):
    def test_coro000(self):

        my_coro000 =coro000()
        self.assertEqual( GtorState.getgeneratorstate(my_coro000), GtorState.GEN_CREATED)

        next(my_coro000)  # prints '-> coroutine started'
        self.assertEqual( GtorState.getgeneratorstate(my_coro000), GtorState.GEN_SUSPENDED)

        try:
            my_coro000.send(42)  # prints '-> coroutine received 42 
            self.assertEqual( GtorState.getgeneratorstate(my_coro000), GtorState.GEN_SUSPENDED)

            self.fail('should have raised StopIteration ')

        except StopIteration:
            self.assertTrue(True, 'On exit a coroutine will throw StopIteration')
            self.assertEqual( GtorState.getgeneratorstate(my_coro000), GtorState.GEN_CLOSED)