old_contents: # _compat.py - Python 2/3 compatibility
  
  import sys
  
  PY2 = sys.version_info.major == 2
  
  
  if PY2:
      string_types = basestring
  
      from itertools import imap as map, izip as zip
  
      def py2_bool_to_nonzero(cls):
          cls.__nonzero__ = cls.__bool__
          del cls.__bool__
          return cls
  
      import copy_reg as copyreg
  
  
  else:
      string_types = str
  
      map, zip = map, zip
  
      def py2_bool_to_nonzero(cls):
          return cls
  
      import copyreg
  
  
  def register_reduce(mcls):
      """Register __reduce__ as reduction function for mcls instances."""
      copyreg.pickle(mcls, mcls.__reduce__)
      return mcls
  
  
  def with_metaclass(meta, *bases):
      """From Jinja2 (BSD licensed).
  
      https://github.com/mitsuhiko/jinja2/blob/master/jinja2/_compat.py
      """
      class metaclass(meta):
          __call__ = type.__call__
          __init__ = type.__init__
          def __new__(cls, name, this_bases, d):
              if this_bases is None:
                  return type.__new__(cls, name, (), d)
              return meta(name, bases, d)
      return metaclass('temporary_class', None, {})
  
new_contents: # _compat.py - Python 2/3 compatibility
  
  import sys
  
  PY2 = (sys.version_info.major == 2)
  
  
  if PY2:
      string_types = basestring
  
      from itertools import imap as map, izip as zip
  
      def py2_bool_to_nonzero(cls):
          cls.__nonzero__ = cls.__bool__
          del cls.__bool__
          return cls
  
      import copy_reg as copyreg
  
  
  else:
      string_types = str
  
      map, zip = map, zip
  
      def py2_bool_to_nonzero(cls):
          return cls
  
      import copyreg
  
  
  def register_reduce(mcls):
      """Register __reduce__ as reduction function for mcls instances."""
      copyreg.pickle(mcls, mcls.__reduce__)
      return mcls
  
  
  def with_metaclass(meta, *bases):
      """From Jinja2 (BSD licensed).
  
      https://github.com/mitsuhiko/jinja2/blob/master/jinja2/_compat.py
      """
      class metaclass(meta):
          __call__ = type.__call__
          __init__ = type.__init__
          def __new__(cls, name, this_bases, d):
              if this_bases is None:
                  return type.__new__(cls, name, (), d)
              return meta(name, bases, d)
      return metaclass('temporary_class', None, {})
  
subject: add parentheses to comparison