examples: Fix Python coding style

* Original commit: espressif/esp-idf@57c54f96f1

examples/protocols/mdns/mdns_example_test.py

@@ -3,28 +3,31 @@ import os
 import sys
 import socket
 import time
-import imp
 import struct
-import dpkt, dpkt.dns
+import dpkt
+import dpkt.dns
 from threading import Thread
 
 
-
 # this is a test case write with tiny-test-fw.
 # to run test cases outside tiny-test-fw,
 # we need to set environment variable `TEST_FW_PATH`,
 # then get and insert `TEST_FW_PATH` to sys path before import FW module
 
+try:
+    import IDF
+except ImportError:
     test_fw_path = os.getenv("TEST_FW_PATH")
     if test_fw_path and test_fw_path not in sys.path:
         sys.path.insert(0, test_fw_path)
-
-import TinyFW
     import IDF
 
+import DUT
+
 g_run_server = True
 g_done = False
 
+
 def mdns_server(esp_host):
     global g_run_server
     global g_done
@@ -52,7 +55,7 @@ def mdns_server(esp_host):
     sock.sendto(resp_dns.pack(),(MCAST_GRP,UDP_PORT))
     while g_run_server:
         try:
-            m=sock.recvfrom( 1024 );
+            m = sock.recvfrom(1024)
             dns = dpkt.dns.DNS(m[0])
             if len(dns.qd) > 0 and dns.qd[0].type == dpkt.dns.DNS_A:
                 if dns.qd[0].name == u'tinytester.local':
@@ -71,6 +74,7 @@ def mdns_server(esp_host):
         except socket.timeout:
             break
 
+
 @IDF.idf_example_test(env_tag="Example_WIFI")
 def test_examples_protocol_mdns(env, extra_data):
     global g_run_server
@@ -93,9 +97,8 @@ def test_examples_protocol_mdns(env, extra_data):
     # 2. get the dut host name (and IP address)
     specific_host = dut1.expect(re.compile(r"mdns hostname set to: \[([^\]]+)\]"), timeout=30)
     specific_host = str(specific_host[0])
-    dut_ip = ""
     try:
-        dut_ip = dut1.expect(re.compile(r" sta ip: ([^,]+),"), timeout=30)
+        dut1.expect(re.compile(r" sta ip: ([^,]+),"), timeout=30)
     except DUT.ExpectTimeout:
         raise ValueError('ENV_TEST_FAILURE: Cannot connect to AP')
     # 3. check the mdns name is accessible
@@ -108,10 +111,11 @@ def test_examples_protocol_mdns(env, extra_data):
             break
     g_run_server = False
     thread1.join()
-    if g_done == False:
+    if g_done is False:
         raise ValueError('Test has failed: did not receive mdns answer within timeout')
     # 4. check DUT output if mdns advertized host is resolved
     dut1.expect(re.compile(r"mdns-test: Query A: tinytester.local resolved to: 127.0.0.1"), timeout=30)
 
+
 if __name__ == '__main__':
     test_examples_protocol_mdns()