[py] Fix flake8 issues and run flake8 on Travis

.travis.yml

@@ -92,6 +92,12 @@ matrix:
     - language: java
       jdk: oraclejdk8
       env: TASK=javadocs
+    - language: python
+      python: 2.7
+      env: TOXENV=flake8
+    - language: python
+      python: 2.7
+      env: TOXENV=docs
     - language: python
       python: 2.7
       env: CHROME=1 TOXENV=py27-chrome
@@ -114,7 +120,10 @@ matrix:
       addons:
         firefox: latest
     - language: python
-      python: 2.7
+      python: 3.5
+      env: TOXENV=flake8
+    - language: python
+      python: 3.5
       env: TOXENV=docs
     - language: python
       python: 3.5
@@ -137,9 +146,6 @@ matrix:
       env: TOXENV=py35-remote
       addons:
         firefox: latest
-    - language: python
-      python: 3.5
-      env: TOXENV=docs
     - language: ruby
       rvm: 2.2.3
       jdk: oraclejdk8

py/selenium/webdriver/firefox/firefox_binary.py

@@ -46,8 +46,13 @@ def __init__(self, firefox_path=None, log_file=None):
         if self._start_cmd is None:
             self._start_cmd = self._get_firefox_start_cmd()
         if not self._start_cmd.strip():
-            raise WebDriverException("Failed to find firefox binary. You can set it by specifying the path to 'firefox_binary':\n\nfrom selenium.webdriver.firefox.firefox_binary import FirefoxBinary\n\n" +
-                            "binary = FirefoxBinary('/path/to/binary')\ndriver = webdriver.Firefox(firefox_binary=binary)")
+            raise WebDriverException(
+                "Failed to find firefox binary. You can set it by specifying "
+                "the path to 'firefox_binary':\n\nfrom "
+                "selenium.webdriver.firefox.firefox_binary import "
+                "FirefoxBinary\n\nbinary = "
+                "FirefoxBinary('/path/to/binary')\ndriver = "
+                "webdriver.Firefox(firefox_binary=binary)")
         # Rather than modifying the environment of the calling Python process
         # copy it and modify as needed.
         self._firefox_env = os.environ.copy()

py/selenium/webdriver/firefox/options.py

@@ -57,7 +57,7 @@ def binary(self, new_binary):
     def binary_location(self):
         return self.binary
 
-    @binary.setter
+    @binary.setter  # noqa
     def binary_location(self, value):
         self.binary = value
 

py/selenium/webdriver/firefox/service.py

@@ -23,7 +23,7 @@ class Service(service.Service):
     GeckoDriver."""
 
     def __init__(self, executable_path, port=0, service_args=None,
-            log_path="geckodriver.log", env=None):
+                 log_path="geckodriver.log", env=None):
         """Creates a new instance of the GeckoDriver remote service proxy.
 
         GeckoDriver provides a HTTP interface speaking the W3C WebDriver

py/selenium/webdriver/firefox/webdriver.py

@@ -28,7 +28,6 @@
 import shutil
 import socket
 import sys
-import types
 
 from .extension_connection import ExtensionConnection
 from contextlib import contextmanager

py/selenium/webdriver/firefox/webelement.py

@@ -30,7 +30,8 @@ def anonymous_children(self):
         on MDN for more information.
 
         """
-        return self._execute("ELEMENT_GET_ANONYMOUS_CHILDREN",
+        return self._execute(
+            "ELEMENT_GET_ANONYMOUS_CHILDREN",
             {"value": None})
 
     def find_anonymous_element_by_attribute(self, name, value):
@@ -43,5 +44,6 @@ def find_anonymous_element_by_attribute(self, name, value):
         on MDN for more information.
 
         """
-        return self._execute("ELEMENT_FIND_ANONYMOUS_ELEMENTS_BY_ATTRIBUTE",
+        return self._execute(
+            "ELEMENT_FIND_ANONYMOUS_ELEMENTS_BY_ATTRIBUTE",
             {"name": name, "value": value})["value"]

py/selenium/webdriver/safari/webdriver.py

@@ -20,7 +20,6 @@
 except ImportError:
     import httplib as http_client
 
-import os
 from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
 from selenium.webdriver.remote.webdriver import WebDriver as RemoteWebDriver
 from .service import Service

py/test/selenium/webdriver/common/network.py

@@ -26,9 +26,9 @@
     def get_interface_ip(ifname):
         def _bytes(value, encoding):
             try:
-                return bytes(value, encoding) # Python 3
+                return bytes(value, encoding)  # Python 3
             except TypeError:
-                return value # Python 2
+                return value  # Python 2
 
         sckt = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
         return socket.inet_ntoa(fcntl.ioctl(

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py{27,35}-{chrome,edge,firefox,ie,phantomjs,remote,safari}, docs
+envlist = py{27,35}-{chrome,edge,firefox,ie,phantomjs,remote,safari}, docs, flake8
 
 [testenv]
 passenv = DISPLAY PYTEST_ADDOPTS
@@ -27,3 +27,8 @@ deps =
   Pygments==1.6
   Sphinx==1.2b1
 commands = sphinx-build -W -b html -d build/doctrees py/docs/source build/docs/api/py {posargs}
+
+[testenv:flake8]
+skip_install = true
+deps = flake8
+commands = flake8 {posargs:py}