#!/usr/bin/env python

"""

(Python >3.3)

This is an example of how we can embed a Python REPL into an asyncio

application. In this example, we have one coroutine that runs in the

background, prints some output and alters a global state. The REPL, which runs

inside another coroutine can access and change this global state, interacting

with the running asyncio application.

The ``patch_stdout`` option makes sure that when another coroutine is writing

to stdout, it won't break the input line, but instead writes nicely above the

prompt.

"""

from __future__ import unicode_literals

from ptpython.repl import embed

import asyncio

loop = asyncio.get_event_loop()

counter = [0]

@asyncio.coroutine

def print_counter():

"""

Coroutine that prints counters and saves it in a global variable.

"""

while True:

print('Counter: %i' % counter[0])

counter[0] += 1

yield from asyncio.sleep(3)

@asyncio.coroutine

def interactive_shell():

"""

Coroutine that starts a Python REPL from which we can access the global

counter variable.

"""

print('You should be able to read and update the "counter[0]" variable from this shell.')

yield from embed(globals=globals(), return_asyncio_coroutine=True, patch_stdout=True)

# Stop the loop when quitting the repl. (Ctrl-D press.)

loop.stop()

def main():

asyncio.ensure_future(print_counter())

asyncio.ensure_future(interactive_shell())

loop.run_forever()

loop.close()

if __name__ == '__main__':

main()