Stop using asyncio.get_event_loop()

It is deprecated in newer Python versions.
Closes #4013.

telethon/client/telegrambaseclient.py

@@ -192,7 +192,7 @@ class TelegramBaseClient(abc.ABC):
             Defaults to `lang_code`.
 
         loop (`asyncio.AbstractEventLoop`, optional):
-            Asyncio event loop to use. Defaults to `asyncio.get_event_loop()`.
+            Asyncio event loop to use. Defaults to `asyncio.get_running_loop()`.
             This argument is ignored.
 
         base_logger (`str` | `logging.Logger`, optional):
@@ -470,7 +470,7 @@ class TelegramBaseClient(abc.ABC):
                 # Join the task (wait for it to complete)
                 await task
         """
-        return asyncio.get_event_loop()
+        return helpers.get_running_loop()
 
     @property
     def disconnected(self: 'TelegramClient') -> asyncio.Future:

telethon/events/inlinequery.py

@@ -4,7 +4,7 @@ import re
 import asyncio
 
 from .common import EventBuilder, EventCommon, name_inner_event
-from .. import utils
+from .. import utils, helpers
 from ..tl import types, functions, custom
 from ..tl.custom.sendergetter import SenderGetter
 
@@ -242,6 +242,6 @@ class InlineQuery(EventBuilder):
             if inspect.isawaitable(obj):
                 return asyncio.ensure_future(obj)
 
-            f = asyncio.get_event_loop().create_future()
+            f = helpers.get_running_loop().create_future()
             f.set_result(obj)
             return f

telethon/helpers.py

@@ -153,7 +153,7 @@ def retry_range(retries, force_retry=True):
     while attempt != retries:
         attempt += 1
         yield attempt
-        
+
 
 
 async def _maybe_await(value):
@@ -426,7 +426,10 @@ class _FileStream(io.IOBase):
 # endregion
 
 def get_running_loop():
-    if sys.version_info[:2] <= (3, 6):
-        return asyncio._get_running_loop()
-
-    return asyncio.get_running_loop()
+    if sys.version_info >= (3, 7):
+        try:
+            return asyncio.get_running_loop()
+        except RuntimeError:
+            return asyncio.get_event_loop_policy().get_event_loop()
+    else:
+        return asyncio.get_event_loop()

telethon/network/connection/connection.py

@@ -155,7 +155,7 @@ class Connection(abc.ABC):
 
                 # Actual TCP connection is performed here.
                 await asyncio.wait_for(
-                    asyncio.get_event_loop().sock_connect(sock=sock, address=address),
+                    helpers.get_running_loop().sock_connect(sock=sock, address=address),
                     timeout=timeout
                 )
 
@@ -190,7 +190,7 @@ class Connection(abc.ABC):
 
             # Actual TCP connection and negotiation performed here.
             await asyncio.wait_for(
-                asyncio.get_event_loop().sock_connect(sock=sock, address=address),
+                helpers.get_running_loop().sock_connect(sock=sock, address=address),
                 timeout=timeout
             )
 
@@ -244,7 +244,7 @@ class Connection(abc.ABC):
         await self._connect(timeout=timeout, ssl=ssl)
         self._connected = True
 
-        loop = asyncio.get_event_loop()
+        loop = helpers.get_running_loop()
         self._send_task = loop.create_task(self._send_loop())
         self._recv_task = loop.create_task(self._recv_loop())
 

telethon/network/mtprotosender.py

@@ -68,7 +68,7 @@ class MTProtoSender:
         # pending futures should be cancelled.
         self._user_connected = False
         self._reconnecting = False
-        self._disconnected = asyncio.get_event_loop().create_future()
+        self._disconnected = helpers.get_running_loop().create_future()
         self._disconnected.set_result(None)
 
         # We need to join the loops upon disconnection
@@ -261,7 +261,7 @@ class MTProtoSender:
             await self._disconnect(error=e)
             raise e
 
-        loop = asyncio.get_event_loop()
+        loop = helpers.get_running_loop()
         self._log.debug('Starting send loop')
         self._send_loop_handle = loop.create_task(self._send_loop())
 
@@ -400,7 +400,7 @@ class MTProtoSender:
                 self._pending_state.clear()
 
                 if self._auto_reconnect_callback:
-                    asyncio.get_event_loop().create_task(self._auto_reconnect_callback())
+                    helpers.get_running_loop().create_task(self._auto_reconnect_callback())
 
                 break
         else:
@@ -425,7 +425,7 @@ class MTProtoSender:
             # gets stuck.
             # TODO It still gets stuck? Investigate where and why.
             self._reconnecting = True
-            asyncio.get_event_loop().create_task(self._reconnect(error))
+            helpers.get_running_loop().create_task(self._reconnect(error))
 
     def _keepalive_ping(self, rnd_id):
         """

telethon/sync.py

@@ -14,7 +14,7 @@ import asyncio
 import functools
 import inspect
 
-from . import events, errors, utils, connection
+from . import events, errors, utils, connection, helpers
 from .client.account import _TakeoutClient
 from .client.telegramclient import TelegramClient
 from .tl import types, functions, custom
@@ -32,7 +32,7 @@ def _syncify_wrap(t, method_name):
     @functools.wraps(method)
     def syncified(*args, **kwargs):
         coro = method(*args, **kwargs)
-        loop = asyncio.get_event_loop()
+        loop = helpers.get_running_loop()
         if loop.is_running():
             return coro
         else: