refine tests

tests/test_udp_src.py

@@ -3,11 +3,16 @@
 import socket
 import socks
 
+
+SERVER_IP = '127.0.0.1'
+SERVER_PORT = 1081
+
+
 if __name__ == '__main__':
     # Test 1: same source port IPv4
     sock_out = socks.socksocket(socket.AF_INET, socket.SOCK_DGRAM,
                                 socket.SOL_UDP)
-    sock_out.set_proxy(socks.SOCKS5, '127.0.0.1', 1081)
+    sock_out.set_proxy(socks.SOCKS5, SERVER_IP, SERVER_PORT)
     sock_out.bind(('127.0.0.1', 9000))
 
     sock_in1 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM,
@@ -35,7 +40,7 @@ if __name__ == '__main__':
     # try again from the same port but IPv6
     sock_out = socks.socksocket(socket.AF_INET, socket.SOCK_DGRAM,
                                 socket.SOL_UDP)
-    sock_out.set_proxy(socks.SOCKS5, '127.0.0.1', 1081)
+    sock_out.set_proxy(socks.SOCKS5, SERVER_IP, SERVER_PORT)
     sock_out.bind(('127.0.0.1', 9000))
 
     sock_in1 = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM,
@@ -62,7 +67,7 @@ if __name__ == '__main__':
     # Test 3: different source ports IPv6
     sock_out = socks.socksocket(socket.AF_INET, socket.SOCK_DGRAM,
                                 socket.SOL_UDP)
-    sock_out.set_proxy(socks.SOCKS5, '127.0.0.1', 1081)
+    sock_out.set_proxy(socks.SOCKS5, SERVER_IP, SERVER_PORT)
     sock_out.bind(('127.0.0.1', 9003))
 
     sock_in1 = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM,