In the one example that had an import before gevent.monkey.patch_all(), move...

In the one example that had an import before gevent.monkey.patch_all(), move it up, as is recommended practice. Whitespace in comment.

examples/concurrent_download.py

@@ -3,16 +3,16 @@
 
 """Spawn multiple workers and wait for them to complete"""
 from __future__ import print_function
-import sys
-
-urls = ['http://www.google.com', 'http://www.yandex.ru', 'http://www.python.org']
-
 import gevent
 from gevent import monkey
 
 # patches stdlib (including socket and ssl modules) to cooperate with other greenlets
 monkey.patch_all()
 
+import sys
+
+urls = ['http://www.google.com', 'http://www.yandex.ru', 'http://www.python.org']
+
 
 if sys.version_info[0] == 3:
     from urllib.request import urlopen

gevent/monkey.py

@@ -272,23 +272,23 @@ def patch_thread(threading=True, _threading_local=True, Event=False, logging=Tru
     """
     # Description of the hang:
     # There is an incompatibility with patching 'thread' and the 'multiprocessing' module:
-	# The problem is that multiprocessing.queues.Queue uses a half-duplex multiprocessing.Pipe,
-	# which is implemented with os.pipe() and _multiprocessing.Connection. os.pipe isn't patched
-	# by gevent, as it returns just a fileno. _multiprocessing.Connection is an internal implementation
-	# class implemented in C, which exposes a 'poll(timeout)' method; under the covers, this issues a
-	# (blocking) select() call: hence the need for a real thread. Except for that method, we could
-	# almost replace Connection with gevent.fileobject.SocketAdapter, plus a trivial
-	# patch to os.pipe (below). Sigh, so close. (With a little work, we could replicate that method)
-
-	# import os
-	# import fcntl
-	# os_pipe = os.pipe
-	# def _pipe():
-	# 	r, w = os_pipe()
-	# 	fcntl.fcntl(r, fcntl.F_SETFL, os.O_NONBLOCK)
-	# 	fcntl.fcntl(w, fcntl.F_SETFL, os.O_NONBLOCK)
-	# 	return r, w
-	# os.pipe = _pipe
+    # The problem is that multiprocessing.queues.Queue uses a half-duplex multiprocessing.Pipe,
+    # which is implemented with os.pipe() and _multiprocessing.Connection. os.pipe isn't patched
+    # by gevent, as it returns just a fileno. _multiprocessing.Connection is an internal implementation
+    # class implemented in C, which exposes a 'poll(timeout)' method; under the covers, this issues a
+    # (blocking) select() call: hence the need for a real thread. Except for that method, we could
+    # almost replace Connection with gevent.fileobject.SocketAdapter, plus a trivial
+    # patch to os.pipe (below). Sigh, so close. (With a little work, we could replicate that method)
+
+    # import os
+    # import fcntl
+    # os_pipe = os.pipe
+    # def _pipe():
+    #   r, w = os_pipe()
+    #   fcntl.fcntl(r, fcntl.F_SETFL, os.O_NONBLOCK)
+    #   fcntl.fcntl(w, fcntl.F_SETFL, os.O_NONBLOCK)
+    #   return r, w
+    # os.pipe = _pipe
 
     patch_module('thread')
     if threading: