[pre-commit] Fix style issues in test scripts under tests/common folder (sonic-net#7360)

* [pre-commit] Fix style issues in test scripts under `tests/common`
folder

What is the motivation for this PR?
pre-commit is a static analysis tool introduced recently. This tool is
not able to do diff-only check. It checks the whole files touched by PR.
We can't blame PR author for legacy issues. That's why currently the
pre-commit check is only optional.

To ensure that we can make pre-commit a mandatory check for PRs
submitted to this repository, we need to fix all the legacy issues
complained by pre-commit.

How did you do it?
This change fixes the style issues of test scripts under `tests/common`
folder

How did you verify/test it?
Any platform specific information?
Supported testbed topology if it's a new test case?

Author: xwjiang-ms

tests/common/cisco_data.py

@@ -1,9 +1,12 @@
 import json
+import re
 from tests.common.reboot import reboot
 
+
 def is_cisco_device(dut):
     return dut.facts["asic_type"] == "cisco-8000"
 
+
 def get_markings_config_file(duthost):
     """
         Get the config file where the ECN markings are enabled or disabled.
@@ -13,31 +16,32 @@ def get_markings_config_file(duthost):
         raise RuntimeError("This is applicable only to cisco platforms.")
 
     hwsku = duthost.facts['hwsku']
-    match = re.search("\-([^-_]+)_", platform)
+    match = re.search(r"\-([^-_]+)_", platform)
     if match:
-       model = match.group(1)
+        model = match.group(1)
     else:
-       raise RuntimeError("Couldn't get the model from platform:{}".format(platform))
+        raise RuntimeError("Couldn't get the model from platform:{}".format(platform))
     config_file = "/usr/share/sonic/device/{}/{}/{}.json".format(platform, hwsku, model)
     return config_file
 
+
 def get_markings_dut(duthost, key_list=['ecn_dequeue_marking', 'ecn_latency_marking', 'voq_allocation_mode']):
     """
         Get the ecn marking values from the duthost.
     """
     config_file = get_markings_config_file(duthost)
     dest_file = "/tmp/"
-    contents = duthost.fetch(src=config_file, dest = dest_file)
+    contents = duthost.fetch(src=config_file, dest=dest_file)
     local_file = contents['dest']
     with open(local_file) as fd:
         json_contents = json.load(fd)
     required_entry = None
     for i in range(len(json_contents['devices'])):
         try:
-             json_contents['devices'][i].get('id')
-             required_entry = i
+            json_contents['devices'][i].get('id')
+            required_entry = i
         except KeyError:
-             continue
+            continue
 
     if required_entry is None:
         raise RuntimeError("Couldnot find the required entry(id) in the config file:{}".format(config_file))
@@ -46,29 +50,30 @@ def get_markings_dut(duthost, key_list=['ecn_dequeue_marking', 'ecn_latency_mark
         original_values[key] = json_contents['devices'][i][key]
     return original_values
 
+
 def setup_markings_dut(duthost, localhost, **kwargs):
     """
         Setup dequeue or latency depending on arguments.
         Applicable to cisco-8000 Platforms only.
     """
     config_file = get_markings_config_file(duthost)
     dest_file = "/tmp/"
-    contents = duthost.fetch(src=config_file, dest = dest_file)
+    contents = duthost.fetch(src=config_file, dest=dest_file)
     local_file = contents['dest']
     with open(local_file) as fd:
         json_contents = json.load(fd)
     required_entry = None
     for i in range(len(json_contents['devices'])):
         try:
-             json_contents['devices'][i].get('id')
-             required_entry = i
+            json_contents['devices'][i].get('id')
+            required_entry = i
         except KeyError:
-             continue
+            continue
 
     if required_entry is None:
         raise RuntimeError("Couldnot find the required entry(id) in the config file:{}".format(config_file))
     reboot_required = False
-    for k,v in kwargs.iteritems():
+    for k, v in kwargs.iteritems():
         if json_contents['devices'][required_entry][k] != v:
             reboot_required = True
             json_contents['devices'][required_entry][k] = v

tests/common/errors.py

@@ -26,7 +26,8 @@ def __init__(self, msg, results=None):
         self.results = results
 
     def _to_string(self):
-        return "{}, Ansible Results =>\n{}".format(self.message, dump_ansible_results(self.results)).encode().decode("utf-8")
+        return "{}, Ansible Results =>\n{}".format(self.message,
+                                                   dump_ansible_results(self.results)).encode().decode("utf-8")
 
     def __str__(self):
         return self._to_string()