Numerous fixes

1. fix comparation with None
2. remove unused imports
3. fix imports order (according to pep8)
4. style fixes (according to pep8)
5. another minor fixes

Author: bayandin

appium/common/exceptions.py

@@ -14,12 +14,13 @@
 
 from selenium.common.exceptions import InvalidSwitchToTargetException
 
+
 class NoSuchContextException(InvalidSwitchToTargetException):
     """
     Thrown when context target to be switched doesn't exist.
 
     To find the current set of active contexts, you can get a list
-    of the active contexts in the following way::
+    of the active contexts in the following way:
 
         print driver.contexts
 

appium/webdriver/common/mobileby.py

@@ -14,6 +14,7 @@
 
 from selenium.webdriver.common.by import By
 
+
 class MobileBy(By):
     IOS_UIAUTOMATION = '-ios uiautomation'
     ANDROID_UIAUTOMATOR = '-android uiautomator'

appium/webdriver/common/multi_action.py

@@ -13,15 +13,15 @@
 # limitations under the License.
 
 
-
 # The Selenium team implemented something like the Multi Action API in the form of
 # "action chains" (https://code.google.com/p/selenium/source/browse/py/selenium/webdriver/common/action_chains.py).
 # These do not quite work for this situation, and do not allow for ad hoc action
 # chaining as the spec requires.
 
+import copy
+
 from appium.webdriver.mobilecommand import MobileCommand as Command
 
-import copy
 
 class MultiAction(object):
     def __init__(self, driver, element=None):
@@ -44,7 +44,7 @@ def add(self, *touch_actions):
             MultiAction(driver).add(a1, a2)
         """
         for touch_action in touch_actions:
-            if self._touch_actions == None:
+            if self._touch_actions is None:
                 self._touch_actions = []
 
             # deep copy, so that once they are in here, the user can't muck about
@@ -68,13 +68,12 @@ def perform(self):
 
         return self
 
-
     @property
     def json_wire_gestures(self):
         actions = []
         for action in self._touch_actions:
             actions.append(action.json_wire_gestures)
-        if self._element != None:
+        if self._element is not None:
             return {'actions': actions, 'elementId': self._element.id}
         else:
             return {'actions': actions}

appium/webdriver/common/touch_action.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 
-
 # The Selenium team implemented a version of the Touch Action API in their code
 # (https://code.google.com/p/selenium/source/browse/py/selenium/webdriver/common/touch_actions.py)
 # but it is deficient in many ways, and does not work in such a way as to be
@@ -22,9 +21,10 @@
 #
 # Theirs is `TouchActions`. Appium's is `TouchAction`.
 
+import copy
+
 from appium.webdriver.mobilecommand import MobileCommand as Command
 
-import copy
 
 class TouchAction(object):
     def __init__(self, driver=None):
@@ -64,11 +64,10 @@ def long_press(self, el=None, x=None, y=None, duration=1000):
     def wait(self, ms=0):
         """Pause for `ms` milliseconds.
         """
-        if ms == None:
+        if ms is None:
             ms = 0
 
-        opts = {}
-        opts['ms'] = ms
+        opts = {'ms': ms}
 
         self._add_action('wait', opts)
 
@@ -91,16 +90,14 @@ def release(self):
     def perform(self):
         """Perform the action by sending the commands to the server to be operated upon
         """
-        params = {}
-        params['actions'] = self._actions
+        params = {'actions': self._actions}
         self._driver.execute(Command.TOUCH_ACTION, params)
 
         # get rid of actions so the object can be reused
         self._actions = []
 
         return self
 
-
     @property
     def json_wire_gestures(self):
         gestures = []
@@ -109,20 +106,20 @@ def json_wire_gestures(self):
         return gestures
 
     def _add_action(self, action, options):
-        gesture = {}
-        gesture['action'] = action
-        gesture['options'] = options
+        gesture = {
+            'action': action,
+            'options': options,
+        }
         self._actions.append(gesture)
 
     def _get_opts(self, element, x, y):
         opts = {}
-        if element != None:
+        if element is not None:
             opts['element'] = element.id
 
         # it makes no sense to have x but no y, or vice versa.
-        if (x == None) | (y == None):
-            x = None
-            y = None
+        if x is None or y is None:
+            x, y = None, None
         opts['x'] = x
         opts['y'] = y
 

appium/webdriver/errorhandler.py

@@ -17,6 +17,7 @@
 
 from appium.common.exceptions import NoSuchContextException
 
+
 class MobileErrorHandler(errorhandler.ErrorHandler):
     def check_response(self, response):
         try:

appium/webdriver/mobilecommand.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+
 class MobileCommand(object):
     CONTEXTS = 'getContexts',
     GET_CURRENT_CONTEXT = 'getCurrentContext',

appium/webdriver/switch_to.py

@@ -16,6 +16,7 @@
 
 from .mobilecommand import MobileCommand
 
+
 class MobileSwitchTo(SwitchTo):
     def context(self, context_name):
         """