Fix remaining flake8 warnings

python/servo/bootstrap_commands.py

@@ -244,7 +244,7 @@ class MachCommands(CommandBase):
 
             with open(path.join(preload_path, preload_filename), 'w') as fd:
                 json.dump(entries, fd, indent=4)
-        except ValueError as e:
+        except ValueError:
             print("Unable to parse chromium HSTS preload list, has the format changed?")
             sys.exit(1)
 
@@ -262,8 +262,8 @@ class MachCommands(CommandBase):
             print("Unable to download the public suffix list; are you connected to the internet?")
             sys.exit(1)
 
-        lines = [l.strip() for l in content.decode("utf8").split("\n")]
-        suffixes = [l for l in lines if not l.startswith("//") and not l == ""]
+        lines = [line.strip() for line in content.decode("utf8").split("\n")]
+        suffixes = [line for line in lines if not line.startswith("//") and not line == ""]
 
         with open(dst_filename, "wb") as fo:
             for suffix in suffixes:
@@ -475,7 +475,7 @@ class MachCommands(CommandBase):
                                     if os.path.exists(crate_path):
                                         try:
                                             delete(crate_path)
-                                        except:
+                                        except (FileNotFoundError, PermissionError):
                                             print(traceback.format_exc())
                                             print("Delete %s failed!" % crate_path)
                             else:

python/servo/devenv_commands.py

@@ -93,8 +93,8 @@ class MachCommands(CommandBase):
         help='Updates the selected package')
     @CommandArgument(
         '--all-packages', '-a', action='store_true',
-        help='Updates all packages. NOTE! This is very likely to break your ' +
-             'working copy, making it impossible to build servo. Only do ' +
+        help='Updates all packages. NOTE! This is very likely to break your '
+             'working copy, making it impossible to build servo. Only do '
              'this if you really know what you are doing.')
     @CommandArgument(
         '--dry-run', '-d', action='store_true',

python/servo/mutation/mutator.py

@@ -138,8 +138,8 @@ class DuplicateLine(Strategy):
         plus_equals_statement = r".+?\s\+\=\s.*"
         minus_equals_statement = r".+?\s\-\=\s.*"
         self._replace_strategy = {
-            'regex': (append_statement + '|' + remove_statement + '|' + push_statement +
-                      '|' + pop_statement + '|' + plus_equals_statement + '|' + minus_equals_statement),
+            'regex': (append_statement + '|' + remove_statement + '|' + push_statement
+                      + '|' + pop_statement + '|' + plus_equals_statement + '|' + minus_equals_statement),
             'replaceString': r"\g<0>\n\g<0>",
         }
 

python/servo/package_commands.py

@@ -30,9 +30,6 @@ from mach.decorators import (
     Command,
 )
 from mach.registrar import Registrar
-# Note: mako cannot be imported at the top level because it breaks mach bootstrap
-sys.path.append(path.join(path.dirname(__file__), "..", "..",
-                          "components", "style", "properties", "Mako-1.1.2-py2.py3-none-any.whl"))
 
 from servo.command_base import (
     archive_deterministically,
@@ -44,6 +41,9 @@ from servo.command_base import (
 )
 from servo.util import delete
 
+# Note: mako cannot be imported at the top level because it breaks mach bootstrap
+sys.path.append(path.join(path.dirname(__file__), "..", "..",
+                          "components", "style", "properties", "Mako-1.1.2-py2.py3-none-any.whl"))
 
 PACKAGES = {
     'android': [
@@ -96,18 +96,18 @@ else:
 
 def get_taskcluster_secret(name):
     url = (
-        os.environ.get("TASKCLUSTER_PROXY_URL", "http://taskcluster") +
-        "/api/secrets/v1/secret/project/servo/" +
-        name
+        os.environ.get("TASKCLUSTER_PROXY_URL", "http://taskcluster")
+        + "/api/secrets/v1/secret/project/servo/"
+        + name
     )
     return json.load(urllib.request.urlopen(url))["secret"]
 
 
 def otool(s):
     o = subprocess.Popen(['/usr/bin/otool', '-L', s], stdout=subprocess.PIPE)
-    for l in o.stdout:
-        if l[0] == '\t':
-            yield l.split(' ', 1)[0][1:]
+    for line in o.stdout:
+        if line[0] == '\t':
+            yield line.split(' ', 1)[0][1:]
 
 
 def listfiles(directory):
@@ -781,7 +781,7 @@ def setup_uwp_signing(ms_app_store, publisher):
         print("Packaging on TC. Using secret certificate")
         pfx = get_taskcluster_secret("windows-codesign-cert/latest")["pfx"]
         open("servo.pfx", "wb").write(base64.b64decode(pfx["base64"]))
-        run_powershell_cmd('Import-PfxCertificate -FilePath .\servo.pfx -CertStoreLocation Cert:\CurrentUser\My')
+        run_powershell_cmd('Import-PfxCertificate -FilePath .\\servo.pfx -CertStoreLocation Cert:\\CurrentUser\\My')
         os.remove("servo.pfx")
 
     # Powershell command that lists all certificates for publisher
@@ -796,7 +796,7 @@ def setup_uwp_signing(ms_app_store, publisher):
         # PowerShell command that creates and install signing certificate for publisher
         cmd = '(New-SelfSignedCertificate -Type Custom -Subject ' + publisher + \
               ' -FriendlyName "Allizom Signing Certificate (temporary)"' + \
-              ' -KeyUsage DigitalSignature -CertStoreLocation "Cert:\CurrentUser\My"' + \
+              ' -KeyUsage DigitalSignature -CertStoreLocation "Cert:\\CurrentUser\\My"' + \
               ' -TextExtension @("2.5.29.37={text}1.3.6.1.5.5.7.3.3", "2.5.29.19={text}")).Thumbprint'
         thumbprint = run_powershell_cmd(cmd)
     elif len(certs) > 1:

python/servo/post_build_commands.py

@@ -161,8 +161,8 @@ class PostBuildCommands(CommandBase):
                     command = rustCommand
 
             # Prepend the debugger args.
-            args = ([command] + self.debuggerInfo.args +
-                    args + params)
+            args = ([command] + self.debuggerInfo.args
+                    + args + params)
         else:
             args = args + params
 
@@ -208,8 +208,8 @@ class PostBuildCommands(CommandBase):
         env = self.build_env()
         env["RUST_BACKTRACE"] = "1"
 
-        servo_cmd = [bin or self.get_nightly_binary_path(nightly) or
-                     self.get_binary_path(release, dev)] + params
+        servo_cmd = [bin or self.get_nightly_binary_path(nightly)
+                     or self.get_binary_path(release, dev)] + params
         rr_cmd = ['rr', '--fatal-errors', 'record']
         try:
             check_call(rr_cmd + servo_cmd)

python/servo/testing_commands.py

@@ -117,8 +117,8 @@ class MachCommands(CommandBase):
                      help="Optionally select test based on "
                           "test file directory")
     @CommandArgument('--render-mode', '-rm', default=DEFAULT_RENDER_MODE,
-                     help="The render mode to be used on all tests. " +
-                          HELP_RENDER_MODE)
+                     help="The render mode to be used on all tests. "
+                          + HELP_RENDER_MODE)
     @CommandArgument('--release', default=False, action="store_true",
                      help="Run with a release build of servo")
     @CommandArgument('--tidy-all', default=False, action="store_true",