old_contents: """
  This module adds several functions for interactive source code inspection.
  """
  
  import inspect
  from sympy.core.compatibility import callable
  
  def source(object):
      """
      Prints the source code of a given object.
      """
      print 'In file: %s' % inspect.getsourcefile(object)
      print inspect.getsource(object)
  
  def get_class(lookup_view):
      """
      Convert a string version of a class name to the object.
  
      For example, get_class('sympy.core.Basic') will return
      class Basic located in module sympy.core
      """
      if isinstance(lookup_view, str):
          # Bail early for non-ASCII strings (they can't be functions).
          lookup_view = lookup_view.encode('ascii')
          mod_name, func_name = get_mod_func(lookup_view)
          if func_name != '':
              lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
              if not callable(lookup_view):
                  raise AttributeError("'%s.%s' is not a callable." % (mod_name, func_name))
      return lookup_view
  
  def get_mod_func(callback):
      """
      splits the string path to a class into a string path to the module
      and the name of the class. For example:
          >>> from sympy.utilities.source import get_mod_func
          >>> get_mod_func('sympy.core.basic.Basic')
          ('sympy.core.basic', 'Basic')
  
      """
      dot = callback.rfind('.')
      if dot == -1:
          return callback, ''
      return callback[:dot], callback[dot+1:]
  
new_contents: """
  This module adds several functions for interactive source code inspection.
  """
  
  import inspect
  from sympy.core.compatibility import callable
  
  def source(object):
      """
      Prints the source code of a given object.
      """
      print 'In file: %s' % inspect.getsourcefile(object)
      print inspect.getsource(object)
  
  def get_class(lookup_view):
      """
      Convert a string version of a class name to the object.
  
      For example, get_class('sympy.core.Basic') will return
      class Basic located in module sympy.core
      """
      if isinstance(lookup_view, str):
          lookup_view = lookup_view
          mod_name, func_name = get_mod_func(lookup_view)
          if func_name != '':
              lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
              if not callable(lookup_view):
                  raise AttributeError("'%s.%s' is not a callable." % (mod_name, func_name))
      return lookup_view
  
  def get_mod_func(callback):
      """
      splits the string path to a class into a string path to the module
      and the name of the class. For example:
          >>> from sympy.utilities.source import get_mod_func
          >>> get_mod_func('sympy.core.basic.Basic')
          ('sympy.core.basic', 'Basic')
  
      """
      dot = callback.rfind('.')
      if dot == -1:
          return callback, ''
      return callback[:dot], callback[dot+1:]
  
subject: remove encode to 'ascii'