Add python linter (flake8) to workflow and fix all files

.flake8

@@ -1,2 +1,7 @@
 [flake8]
 max-line-length = 132
+exclude = third_party
+          .*
+          out/*
+          scripts/idl/*
+          ./examples/common/QRCode/*

.github/workflows/lint.yml

@@ -213,3 +213,9 @@ jobs:
               if: always()
               run: |
                   git grep -n 'emberAfWriteAttribute' -- './*' ':(exclude).github/workflows/lint.yml' ':(exclude)src/app/util/af.h' ':(exclude)zzz_generated/app-common/app-common/zap-generated/attributes/Accessors.cpp' ':(exclude)src/app/zap-templates/templates/app/attributes/Accessors-src.zapt' ':(exclude)src/app/util/attribute-table.cpp' ':(exclude)examples/common/pigweed/rpc_services/Attributes.h' ':(exclude)src/app/util/attribute-table.h' ':(exclude)src/app/util/ember-compatibility-functions.cpp' && exit 1 || exit 0
+
+            # Run python Linter (flake8) and verify python files
+            - name: Check for errors using flake8 Python linter
+              if: always()
+              run: |
+                  flake8 --extend-ignore=E501,W391

build/chip/java/tests/test.py

@@ -18,7 +18,6 @@
 
 import json
 import os
-import subprocess
 import unittest
 from os import path
 

build/chip/linux/gen_gdbus_wrapper.py

@@ -65,10 +65,10 @@ def main(argv):
                       ] + extra_args + [options.input_file]
         subprocess.check_call(gdbus_args)
         sed_args = ["sed", "-i",
-                    "s/config\.h/BuildConfig.h/g", options.output_c]
+                    r"s/config\.h/BuildConfig.h/g", options.output_c]
         if sys.platform == "darwin":
             sed_args = ["sed", "-i", "",
-                        "s/config\.h/BuildConfig.h/g", options.output_c]
+                        r"s/config\.h/BuildConfig.h/g", options.output_c]
         subprocess.check_call(sed_args)
 
     if options.output_h:

build/config/linux/pkg-config.py

@@ -108,7 +108,7 @@ def MatchesAnyRegexp(flag, list_of_regexps):
     """Returns true if the first argument matches any regular expression in the
     given list."""
     for regexp in list_of_regexps:
-        if regexp.search(flag) != None:
+        if regexp.search(flag) is not None:
             return True
     return False
 
@@ -145,7 +145,7 @@ def main():
 
     # Make a list of regular expressions to strip out.
     strip_out = []
-    if options.strip_out != None:
+    if options.strip_out is not None:
         for regexp in options.strip_out:
             strip_out.append(re.compile(regexp))
 

credentials/fetch-paa-certs-from-dcl.py

@@ -26,7 +26,6 @@
 import re
 import subprocess
 import sys
-from contextlib import nullcontext
 
 import click
 import requests
@@ -123,12 +122,17 @@ def use_dcld(dcld, production, cmdlist):
 @click.command()
 @click.help_option('-h', '--help')
 @optgroup.group('Input data sources', cls=RequiredMutuallyExclusiveOptionGroup)
-@optgroup.option('--use-main-net-dcld', type=str, default='', metavar='PATH', help="Location of `dcld` binary, to use `dcld` for mirroring MainNet.")
-@optgroup.option('--use-test-net-dcld', type=str, default='', metavar='PATH', help="Location of `dcld` binary, to use `dcld` for mirroring TestNet.")
-@optgroup.option('--use-main-net-http', is_flag=True, type=str, help="Use RESTful API with HTTPS against public MainNet observer.")
-@optgroup.option('--use-test-net-http', is_flag=True, type=str, help="Use RESTful API with HTTPS against public TestNet observer.")
+@optgroup.option('--use-main-net-dcld', type=str, default='', metavar='PATH',
+                 help="Location of `dcld` binary, to use `dcld` for mirroring MainNet.")
+@optgroup.option('--use-test-net-dcld', type=str, default='', metavar='PATH',
+                 help="Location of `dcld` binary, to use `dcld` for mirroring TestNet.")
+@optgroup.option('--use-main-net-http', is_flag=True, type=str,
+                 help="Use RESTful API with HTTPS against public MainNet observer.")
+@optgroup.option('--use-test-net-http', is_flag=True, type=str,
+                 help="Use RESTful API with HTTPS against public TestNet observer.")
 @optgroup.group('Optional arguments')
-@optgroup.option('--paa-trust-store-path', default='paa-root-certs', type=str, metavar='PATH', help="PAA trust store path (default: paa-root-certs)")
+@optgroup.option('--paa-trust-store-path', default='paa-root-certs', type=str, metavar='PATH',
+                 help="PAA trust store path (default: paa-root-certs)")
 def main(use_main_net_dcld, use_test_net_dcld, use_main_net_http, use_test_net_http, paa_trust_store_path):
     """DCL PAA mirroring tools"""
 
@@ -163,7 +167,8 @@ def main(use_main_net_dcld, use_test_net_dcld, use_main_net_http, use_test_net_h
 
         if use_rest:
             response = requests.get(
-                f"{rest_node_url}/dcl/pki/certificates/{paa['subject']}/{paa['subjectKeyId']}").json()["approvedCertificates"]["certs"][0]
+                f"{rest_node_url}/dcl/pki/certificates/"
+                f"{paa['subject']}/{paa['subjectKeyId']}").json()["approvedCertificates"]["certs"][0]
             certificate = response["pemCert"]
             subject = response["subjectAsText"]
         else:

docs/_extensions/external_content.py

@@ -81,7 +81,7 @@ def adjust_includes(
 
     def _adjust_path(path):
         # ignore absolute paths, section links, hyperlinks and same folder
-        if path.startswith(("/", "#", "http", "www")) or not "/" in path:
+        if path.startswith(("/", "#", "http", "www")) or "/" not in path:
             return path
 
         # for files that are being copied modify reference to and out of /docs