cpython/Lib/asyncio/__main__.py
Yury Selivanov 16cefb0bc7
bpo-37028: asyncio REPL; activated via 'python -m asyncio'. (GH-13472)
This makes it easy to play with asyncio APIs with simply
using async/await in the REPL.
2019-05-27 13:42:29 +02:00

126 lines
3.3 KiB
Python

import ast
import asyncio
import code
import concurrent.futures
import inspect
import sys
import threading
import types
import warnings
from . import futures
class AsyncIOInteractiveConsole(code.InteractiveConsole):
def __init__(self, locals, loop):
super().__init__(locals)
self.compile.compiler.flags |= ast.PyCF_ALLOW_TOP_LEVEL_AWAIT
self.loop = loop
def runcode(self, code):
future = concurrent.futures.Future()
def callback():
global repl_future
global repl_future_interrupted
repl_future = None
repl_future_interrupted = False
func = types.FunctionType(code, self.locals)
try:
coro = func()
except SystemExit:
raise
except KeyboardInterrupt as ex:
repl_future_interrupted = True
future.set_exception(ex)
return
except BaseException as ex:
future.set_exception(ex)
return
if not inspect.iscoroutine(coro):
future.set_result(coro)
return
try:
repl_future = self.loop.create_task(coro)
futures._chain_future(repl_future, future)
except BaseException as exc:
future.set_exception(exc)
loop.call_soon_threadsafe(callback)
try:
return future.result()
except SystemExit:
raise
except BaseException:
if repl_future_interrupted:
self.write("\nKeyboardInterrupt\n")
else:
self.showtraceback()
class REPLThread(threading.Thread):
def run(self):
try:
banner = (
f'asyncio REPL {sys.version} on {sys.platform}\n'
f'Use "await" directly instead of "asyncio.run()".\n'
f'Type "help", "copyright", "credits" or "license" '
f'for more information.\n'
f'{getattr(sys, "ps1", ">>> ")}import asyncio'
)
console.interact(
banner=banner,
exitmsg='exiting asyncio REPL...')
finally:
warnings.filterwarnings(
'ignore',
message=r'^coroutine .* was never awaited$',
category=RuntimeWarning)
loop.call_soon_threadsafe(loop.stop)
if __name__ == '__main__':
loop = asyncio.new_event_loop()
asyncio.set_event_loop(loop)
repl_locals = {'asyncio': asyncio}
for key in {'__name__', '__package__',
'__loader__', '__spec__',
'__builtins__', '__file__'}:
repl_locals[key] = locals()[key]
console = AsyncIOInteractiveConsole(repl_locals, loop)
repl_future = None
repl_future_interrupted = False
try:
import readline # NoQA
except ImportError:
pass
repl_thread = REPLThread()
repl_thread.daemon = True
repl_thread.start()
while True:
try:
loop.run_forever()
except KeyboardInterrupt:
if repl_future and not repl_future.done():
repl_future.cancel()
repl_future_interrupted = True
continue
else:
break