old_contents: # -*- coding: utf-8 -*-
  
  from __future__ import unicode_literals
  
  from .settings import IE_COMPATIBILITY_MODE, IE_ACTIVATION_METHOD
  
  
  class GoogleChromeFrameIEMiddleware(object):
      """
      Middleware that sets the X-UA-Compatible HTTP header in HTTP responses.
  
      Does not set the header if the response contains a `gcframe_exempt`
      value set to `True`.
  
      This header (conditionally) activates Google Chrome Frame in
      Internet Explorer, if it is installed. Otherwise, IE will use the
      highest compatibility mode that it has.
  
      The ``GCF_IE_COMPATIBILITY_MODE`` setting or a ``compat_mode``
      keyword argument can alter the behavior of compatibility mode. See
      the following URL for an example.
  
      See http://msdn.microsoft.com/library/cc817574.aspx for further
      details.
  
      The ``GCF_IE_ACTIVATION_METHOD`` setting or an ``act_method``
      keyword argument can alter the behavior of GCF activation. See
      the following URL for an example.
  
      See http://www.chromium.org/developers/how-tos/chrome-frame-getting-started
  
      """
  
      def __init__(self, compat_mode=IE_COMPATIBILITY_MODE, act_method=IE_ACTIVATION_METHOD):
          self.compat_mode = compat_mode
          self.act_method = act_method
  
      def process_response(self, request, response):
  
          # Don't set the header if the @gcframe_exempt decorator was used,
          # or if it has already been set. (The @gcframe decorator may
          # have been used to set a custom act_method value.)
          if not getattr(response, 'gcframe_exempt', False) \
          and not response.has_header('X-UA-Compatible'):
  
              # At this point we know they are activating GCF.
              content = 'chrome={0}'.format(self.act_method)
  
              # Now prepend the compatibility mode parameter/value pair if
              # they want it. (They do by default.) Note that this pair
              # must be first in the content. See
              # http://www.chromium.org/developers/how-tos/chrome-frame-getting-started
              if not self.compat_mode == None:
                  content = 'IE={0},{1}'.format(self.compat_mode, content)
  
              response['X-UA-Compatible'] = content
  
          return response
  
new_contents: # -*- coding: utf-8 -*-
  
  from __future__ import unicode_literals
  
  from .settings import IE_COMPATIBILITY_MODE, IE_ACTIVATION_METHOD
  
  
  class GoogleChromeFrameIEMiddleware(object):
      """
      Middleware that sets the X-UA-Compatible HTTP header in HTTP responses.
  
      Does not set the header if the response contains a `gcframe_exempt`
      value set to `True`.
  
      This header (conditionally) activates Google Chrome Frame in
      Internet Explorer, if it is installed. Otherwise, IE will use the
      highest compatibility mode that it has.
  
      The ``GCF_IE_COMPATIBILITY_MODE`` setting or a ``compat_mode``
      keyword argument can alter the behavior of compatibility mode. See
      the following URL for an example.
  
      See http://msdn.microsoft.com/library/cc817574.aspx for further
      details.
  
      The ``GCF_IE_ACTIVATION_METHOD`` setting or an ``act_method``
      keyword argument can alter the behavior of GCF activation. See
      the following URL for an example.
  
      See http://www.chromium.org/developers/how-tos/chrome-frame-getting-started
  
      """
  
      def __init__(self, compat_mode=IE_COMPATIBILITY_MODE, act_method=IE_ACTIVATION_METHOD):
          self.compat_mode = compat_mode
          self.act_method = act_method
  
      def process_response(self, request, response):
  
          # Don't set the header if the @gcframe_exempt decorator was used,
          # or if it has already been set. (The @gcframe decorator may
          # have been used to set a custom act_method value.)
          if not getattr(response, 'gcframe_exempt', False) \
          and not response.has_header('X-UA-Compatible'):
  
              # At this point we know they are activating GCF.
              content = 'chrome={0}'.format(self.act_method)
  
              # Now prepend the compatibility mode parameter/value pair if
              # they want it. (They do by default.) Note that this pair
              # must be first in the content. See
              # http://www.chromium.org/developers/how-tos/chrome-frame-getting-started
              if self.compat_mode is not None:
                  content = 'IE={0},{1}'.format(self.compat_mode, content)
  
              response['X-UA-Compatible'] = content
  
          return response
  
subject: Change to more idiomatic None comparison.