Rename isasyncgen to _isasyncgen.

docs/topics/coroutines.rst

@@ -100,7 +100,7 @@ synchronous :meth:`~scrapy.spiders.Spider.start_requests`.
 Another option is to make separate methods for normal and asynchronous
 iterables and choose one at run time::
 
-    from scrapy.utils.defer import isasyncgen
+    from inspect import isasyncgen
 
     class ProcessStartRequestsAsyncGenMiddleware:
         def _normal_process_start_requests(self, start_requests, spider):

scrapy/core/engine.py

@@ -14,7 +14,7 @@ from scrapy import signals
 from scrapy.core.scraper import Scraper
 from scrapy.exceptions import DontCloseSpider
 from scrapy.http import Response, Request
-from scrapy.utils.defer import deferred_from_coro, isasyncgen
+from scrapy.utils.defer import deferred_from_coro, _isasyncgen
 from scrapy.utils.misc import load_object
 from scrapy.utils.reactor import CallLaterOnce
 from scrapy.utils.log import logformatter_adapter, failure_to_exc_info
@@ -27,7 +27,7 @@ class Slot:
     def __init__(self, start_requests, close_if_idle, nextcall, scheduler):
         self.closing = False
         self.inprogress = set()  # requests in progress
-        if isasyncgen(start_requests):
+        if _isasyncgen(start_requests):
             self.start_requests = start_requests
         else:
             self.start_requests = iter(start_requests)
@@ -131,7 +131,7 @@ class ExecutionEngine:
 
         if slot.start_requests and not self._needs_backout(spider):
             try:
-                if isasyncgen(slot.start_requests):
+                if _isasyncgen(slot.start_requests):
                     request = yield deferred_from_coro(slot.start_requests.__anext__())
                 else:
                     request = next(slot.start_requests)

scrapy/utils/defer.py

@@ -175,7 +175,7 @@ def maybeDeferred_coro(f, *args, **kw):
         return defer.succeed(result)
 
 
-def isasyncgen(o):
+def _isasyncgen(o):
     """ Returns inspect.isasyncgen() result if it's available (requires Python 3.6),
     otherwise returns False.
     """

scrapy/utils/spider.py

@@ -2,7 +2,7 @@ import logging
 import inspect
 
 from scrapy.spiders import Spider
-from scrapy.utils.defer import deferred_from_coro, isasyncgen
+from scrapy.utils.defer import deferred_from_coro, _isasyncgen
 from scrapy.utils.misc import arg_to_iter
 try:
     from scrapy.utils.asyncgen import collect_asyncgen
@@ -14,7 +14,7 @@ logger = logging.getLogger(__name__)
 
 
 def iterate_spider_output(result):
-    if collect_asyncgen and isasyncgen(result):
+    if collect_asyncgen and _isasyncgen(result):
         d = deferred_from_coro(collect_asyncgen(result))
         d.addCallback(iterate_spider_output)
         return d