Fix /python/servo code formatting.

(My editor screams at me for flake8 lint errors.)

6 files changed, 85 insertions, 76 deletions

diff --git a/python/servo/bootstrap_commands.py b/python/servo/bootstrap_commands.py
index bf83803afac..1d682adb7f5 100644
--- a/python/servo/bootstrap_commands.py
+++ b/python/servo/bootstrap_commands.py
@@ -16,6 +16,7 @@ from mach.decorators import (
 
 from servo.command_base import CommandBase, cd
 
+
 def host_triple():
     os_type = subprocess.check_output(["uname", "-s"]).strip().lower()
     if os_type == "linux":
@@ -39,8 +40,10 @@ def host_triple():
 
     return "%s-%s" % (cpu_type, os_type)
 
+
 def download(desc, src, dst):
     recved = [0]
+
     def report(count, bsize, fsize):
         recved[0] += bsize
         pct = recved[0] * 100.0 / fsize
@@ -53,6 +56,7 @@ def download(desc, src, dst):
     if not dumb:
         print()
 
+
 def extract(src, dst, movedir=None):
     tarfile.open(src).extractall(dst)
 
@@ -65,6 +69,7 @@ def extract(src, dst, movedir=None):
 
     os.remove(src)
 
+
 @CommandProvider
 class MachCommands(CommandBase):
     @Command('env',
@@ -95,7 +100,8 @@ class MachCommands(CommandBase):
             shutil.rmtree(rust_dir)
         os.mkdir(rust_dir)
 
-        snapshot_hash = open(path.join(self.context.topdir, "rust-snapshot-hash")).read().strip()
+        filename = path.join(self.context.topdir, "rust-snapshot-hash")
+        snapshot_hash = open(filename).read().strip()
         snapshot_path = "%s-%s.tar.gz" % (snapshot_hash, host_triple())
         snapshot_url = "https://servo-rust.s3.amazonaws.com/%s" % snapshot_path
         tgz_file = path.join(rust_dir, path.basename(snapshot_path))
@@ -147,10 +153,14 @@ class MachCommands(CommandBase):
                 module_path = components[1]
                 if path.exists(module_path):
                     with cd(module_path):
-                        output = subprocess.check_output(["git", "status", "--porcelain"])
+                        output = subprocess.check_output(
+                            ["git", "status", "--porcelain"])
                         if len(output) != 0:
-                            print("error: submodule %s is not clean" % module_path)
+                            print("error: submodule %s is not clean"
+                                  % module_path)
                             print("\nClean the submodule and try again.")
                             return 1
-        subprocess.check_call(["git", "submodule", "--quiet", "sync", "--recursive"])
-        subprocess.check_call(["git", "submodule", "update", "--init", "--recursive"])
+        subprocess.check_call(
+            ["git", "submodule", "--quiet", "sync", "--recursive"])
+        subprocess.check_call(
+            ["git", "submodule", "update", "--init", "--recursive"])
diff --git a/python/servo/build_commands.py b/python/servo/build_commands.py
index 3b34e575443..d31b5a64d89 100644
--- a/python/servo/build_commands.py
+++ b/python/servo/build_commands.py
@@ -1,16 +1,9 @@
 from __future__ import print_function, unicode_literals
 
-import json
-import os
 import os.path as path
-import shutil
 import subprocess
-import sys
-import tarfile
 from time import time
-import urllib
 
-from mach.registrar import Registrar
 from mach.decorators import (
     CommandArgument,
     CommandProvider,
@@ -19,6 +12,7 @@ from mach.decorators import (
 
 from servo.command_base import CommandBase, cd
 
+
 @CommandProvider
 class MachCommands(CommandBase):
     @Command('build',
@@ -50,7 +44,9 @@ class MachCommands(CommandBase):
             opts += ["-v"]
 
         build_start = time()
-        status = subprocess.call(["cargo", "build"] + opts, env=self.build_env())
+        status = subprocess.call(
+            ["cargo", "build"] + opts,
+            env=self.build_env())
         elapsed = time() - build_start
 
         print("Build completed in %0.2fs" % elapsed)
@@ -90,7 +86,8 @@ class MachCommands(CommandBase):
         opts = []
         if jobs is not None:
             opts += ["-j", jobs]
-        return subprocess.call(["cargo", "test", "--no-run"], env=self.build_env())
+        return subprocess.call(
+            ["cargo", "test", "--no-run"], env=self.build_env())
 
     @Command('clean',
              description='Clean the build directory.',
diff --git a/python/servo/command_base.py b/python/servo/command_base.py
index a5b4a555190..dd02446eb63 100644
--- a/python/servo/command_base.py
+++ b/python/servo/command_base.py
@@ -1,22 +1,23 @@
 import os
 from os import path
+import contextlib
 import subprocess
 import sys
 import toml
 
 from mach.registrar import Registrar
 
-class cd:
-    """Context manager for changing the current working directory"""
-    def __init__(self, newPath):
-        self.newPath = newPath
 
-    def __enter__(self):
-        self.savedPath = os.getcwd()
-        os.chdir(self.newPath)
+@contextlib.contextmanager
+def cd(new_path):
+    """Context manager for changing the current working directory"""
+    previous_path = os.getcwd()
+    try:
+        os.chdir(new_path)
+        yield
+    finally:
+        os.chdir(previous_path)
 
-    def __exit__(self, etype, value, traceback):
-        os.chdir(self.savedPath)
 
 class CommandBase(object):
     """Base class for mach command providers.
@@ -42,23 +43,29 @@ class CommandBase(object):
         self.config["tools"].setdefault("rust-root", "")
         self.config["tools"].setdefault("cargo-root", "")
         if not self.config["tools"]["system-rust"]:
-            self.config["tools"]["rust-root"] = path.join(context.topdir, "rust")
+            self.config["tools"]["rust-root"] = path.join(
+                context.topdir, "rust")
         if not self.config["tools"]["system-cargo"]:
-            self.config["tools"]["cargo-root"] = path.join(context.topdir, "cargo")
+            self.config["tools"]["cargo-root"] = path.join(
+                context.topdir, "cargo")
 
     def build_env(self):
         """Return an extended environment dictionary."""
         env = os.environ.copy()
         extra_path = []
         extra_lib = []
-        if not self.config["tools"]["system-rust"] or self.config["tools"]["rust-root"]:
+        if not self.config["tools"]["system-rust"] \
+                or self.config["tools"]["rust-root"]:
             extra_path += [path.join(self.config["tools"]["rust-root"], "bin")]
             extra_lib += [path.join(self.config["tools"]["rust-root"], "lib")]
-        if not self.config["tools"]["system-cargo"] or self.config["tools"]["cargo-root"]:
-            extra_path += [path.join(self.config["tools"]["cargo-root"], "bin")]
+        if not self.config["tools"]["system-cargo"] \
+                or self.config["tools"]["cargo-root"]:
+            extra_path += [
+                path.join(self.config["tools"]["cargo-root"], "bin")]
 
         if extra_path:
-            env["PATH"] = "%s%s%s" % (os.pathsep.join(extra_path), os.pathsep, env["PATH"])
+            env["PATH"] = "%s%s%s" % (
+                os.pathsep.join(extra_path), os.pathsep, env["PATH"])
         if extra_lib:
             if sys.platform == "darwin":
                 env["DYLD_LIBRARY_PATH"] = "%s%s%s" % \
@@ -74,7 +81,8 @@ class CommandBase(object):
         return env
 
     def ensure_bootstrapped(self):
-        if self.context.bootstrapped: return
+        if self.context.bootstrapped:
+            return
 
         submodules = subprocess.check_output(["git", "submodule", "status"])
         for line in submodules.split('\n'):
@@ -82,13 +90,16 @@ class CommandBase(object):
             if len(components) > 1 and components[0].startswith(('-', '+')):
                 module_path = components[1]
                 subprocess.check_call(["git", "submodule", "update",
-                                       "--init", "--recursive", "--", module_path])
+                                       "--init", "--recursive",
+                                       "--", module_path])
 
         if not self.config["tools"]["system-rust"] and \
-           not path.exists(path.join(self.context.topdir, "rust", "bin", "rustc")):
+           not path.exists(path.join(
+                self.context.topdir, "rust", "bin", "rustc")):
             Registrar.dispatch("bootstrap-rust", context=self.context)
         if not self.config["tools"]["system-cargo"] and \
-           not path.exists(path.join(self.context.topdir, "cargo", "bin", "cargo")):
+           not path.exists(path.join(
+                self.context.topdir, "cargo", "bin", "cargo")):
             Registrar.dispatch("bootstrap-cargo", context=self.context)
 
         self.context.bootstrapped = True
diff --git a/python/servo/devenv_commands.py b/python/servo/devenv_commands.py
index 402c18f2767..f186427ba4a 100644
--- a/python/servo/devenv_commands.py
+++ b/python/servo/devenv_commands.py
@@ -1,16 +1,7 @@
 from __future__ import print_function, unicode_literals
 
-import json
-import os
-import os.path as path
-import shutil
 import subprocess
-import sys
-import tarfile
-from time import time
-import urllib
 
-from mach.registrar import Registrar
 from mach.decorators import (
     CommandArgument,
     CommandProvider,
@@ -19,14 +10,16 @@ from mach.decorators import (
 
 from servo.command_base import CommandBase
 
+
 @CommandProvider
 class MachCommands(CommandBase):
     @Command('cargo',
              description='Run Cargo',
              category='devenv',
              allow_all_args=True)
-    @CommandArgument('params', default=None, nargs='...',
-                     help="Command-line arguments to be passed through to Cargo")
+    @CommandArgument(
+        'params', default=None, nargs='...',
+        help="Command-line arguments to be passed through to Cargo")
     def cargo(self, params):
         return subprocess.call(["cargo"] + params,
                                env=self.build_env())
@@ -35,7 +28,8 @@ class MachCommands(CommandBase):
              description='Run the Rust compiler',
              category='devenv',
              allow_all_args=True)
-    @CommandArgument('params', default=None, nargs='...',
-                     help="Command-line arguments to be passed through to rustc")
+    @CommandArgument(
+        'params', default=None, nargs='...',
+        help="Command-line arguments to be passed through to rustc")
     def rustc(self, params):
         return subprocess.call(["rustc"] + params, env=self.build_env())
diff --git a/python/servo/post_build_commands.py b/python/servo/post_build_commands.py
index 276a772c787..b09a3daaa15 100644
--- a/python/servo/post_build_commands.py
+++ b/python/servo/post_build_commands.py
@@ -1,16 +1,8 @@
 from __future__ import print_function, unicode_literals
 
-import json
-import os
 import os.path as path
-import shutil
 import subprocess
-import sys
-import tarfile
-from time import time
-import urllib
 
-from mach.registrar import Registrar
 from mach.decorators import (
     CommandArgument,
     CommandProvider,
@@ -19,14 +11,16 @@ from mach.decorators import (
 
 from servo.command_base import CommandBase
 
+
 @CommandProvider
 class MachCommands(CommandBase):
     @Command('run',
              description='Run Servo',
              category='post-build',
              allow_all_args=True)
-    @CommandArgument('params', default=None, nargs='...',
-                     help="Command-line arguments to be passed through to Servo")
+    @CommandArgument(
+        'params', default=None, nargs='...',
+        help="Command-line arguments to be passed through to Servo")
     def run(self, params):
         subprocess.check_call([path.join("target", "servo")] + params,
                               env=self.build_env())
@@ -35,10 +29,10 @@ class MachCommands(CommandBase):
              description='Generate documentation',
              category='post-build',
              allow_all_args=True)
-    @CommandArgument('params', default=None, nargs='...',
-                     help="Command-line arguments to be passed through to cargo doc")
+    @CommandArgument(
+        'params', default=None, nargs='...',
+        help="Command-line arguments to be passed through to cargo doc")
     def doc(self, params):
         self.ensure_bootstrapped()
         return subprocess.call(["cargo", "doc"] + params,
                                env=self.build_env())
-
diff --git a/python/servo/testing_commands.py b/python/servo/testing_commands.py
index 56eb1377f7b..3d20aeb27da 100644
--- a/python/servo/testing_commands.py
+++ b/python/servo/testing_commands.py
@@ -1,14 +1,9 @@
 from __future__ import print_function, unicode_literals
 
-import json
 import os
 import os.path as path
-import shutil
 import subprocess
-import sys
-import tarfile
 from time import time
-import urllib
 
 from mach.registrar import Registrar
 from mach.decorators import (
@@ -20,6 +15,7 @@ from mach.decorators import (
 from servo.command_base import CommandBase
 import tidy
 
+
 @CommandProvider
 class MachCommands(CommandBase):
     def __init__(self, context):
@@ -28,13 +24,15 @@ class MachCommands(CommandBase):
             self.context.built_tests = False
 
     def ensure_built_tests(self):
-        if self.context.built_tests: return
+        if self.context.built_tests:
+            return
         Registrar.dispatch('build-tests', context=self.context)
         self.context.built_tests = True
 
     def find_test(self, prefix):
-        candidates = [f for f in os.listdir(path.join(self.context.topdir, "target"))
-                      if f.startswith(prefix + "-")]
+        candidates = [
+            f for f in os.listdir(path.join(self.context.topdir, "target"))
+            if f.startswith(prefix + "-")]
         if candidates:
             return path.join(self.context.topdir, "target", candidates[0])
         return None
@@ -61,8 +59,9 @@ class MachCommands(CommandBase):
              allow_all_args=True)
     @CommandArgument('test_name', default=None, nargs="...",
                      help="Only run tests that match this pattern")
-    @CommandArgument('params', default=None, nargs="...",
-                     help="Command-line arguments to be passed to the test harness")
+    @CommandArgument(
+        'params', default=None, nargs="...",
+        help="Command-line arguments to be passed to the test harness")
     def test_unit(self, test_name=None, params=None):
         if params is None:
             params = []
@@ -79,8 +78,9 @@ class MachCommands(CommandBase):
                      help="'cpu' or 'gpu' (default both)")
     @CommandArgument('test_name', default=None, nargs="?",
                      help="Only run tests that match this pattern")
-    @CommandArgument('servo_params', default=None, nargs="...",
-                     help="Command-line arguments to be passed through to Servo")
+    @CommandArgument(
+        'servo_params', default=None, nargs="...",
+        help="Command-line arguments to be passed through to Servo")
     def test_ref(self, kind=None, test_name=None, servo_params=None):
         self.ensure_bootstrapped()
         self.ensure_built_tests()
@@ -103,7 +103,8 @@ class MachCommands(CommandBase):
 
         print("Reference tests completed in %0.2fs" % elapsed)
 
-        if error: return 1
+        if error:
+            return 1
 
     @Command('test-content',
              description='Run the content tests',
@@ -138,10 +139,12 @@ class MachCommands(CommandBase):
              description='Run the web platform tests',
              category='testing',
              allow_all_args=True)
-    @CommandArgument('params', default=None, nargs='...',
-                     help="Command-line arguments to be passed through to wpt/run.sh")
+    @CommandArgument(
+        'params', default=None, nargs='...',
+        help="Command-line arguments to be passed through to wpt/run.sh")
     def test_wpt(self, params=None):
         if params is None:
             params = []
-        return subprocess.call(["bash", path.join("tests", "wpt", "run.sh")] + params,
-                               env=self.build_env())
+        return subprocess.call(
+            ["bash", path.join("tests", "wpt", "run.sh")] + params,
+            env=self.build_env())