Fix str/bytes issue.

 * udp_client.py
 * gevent/subprocess.py

examples/udp_client.py

@@ -16,6 +16,6 @@ message = ' '.join(sys.argv[1:])
 sock = socket.socket(type=socket.SOCK_DGRAM)
 sock.connect(address)
 print('Sending %s bytes to %s:%s' % ((len(message), ) + address))
-sock.send(message)
+sock.send(message.encode())
 data, address = sock.recvfrom(8192)
 print('%s:%s: got %r' % (address + (data, )))

gevent/subprocess.py

@@ -143,13 +143,13 @@ def check_output(*popenargs, **kwargs):
     The arguments are the same as for the Popen constructor.  Example:
 
     >>> check_output(["ls", "-1", "/dev/null"])
-    '/dev/null\n'
+    b'/dev/null\n'
 
     The stdout argument is not allowed as it is used internally.
     To capture standard error in the result, use stderr=STDOUT.
 
     >>> check_output(["/bin/sh", "-c", "echo hello world"], stderr=STDOUT)
-    'hello world\n'
+    b'hello world\n'
     """
     if 'stdout' in kwargs:
         raise ValueError('stdout argument not allowed, it will be overridden.')

greentest/test__example_udp_client.py

@@ -12,7 +12,7 @@ class Test_udp_client(TestCase):
 
         def handle(message, address):
             log.append(message)
-            server.sendto('reply-from-server', address)
+            server.sendto(b'reply-from-server', address)
 
         server = DatagramServer('127.0.0.1:9000', handle)
         server.start()
@@ -20,7 +20,7 @@ class Test_udp_client(TestCase):
             run([sys.executable, '-u', 'udp_client.py', 'Test_udp_client'], timeout=10, cwd='../examples/')
         finally:
             server.close()
-        self.assertEqual(log, ['Test_udp_client'])
+        self.assertEqual(log, [b'Test_udp_client'])
 
 
 if __name__ == '__main__':