parameters: (_alias, **options)
docstring: Get a lexer by an alias.
  
      Raises ClassNotFound if not found.
docstring_summary: Get a lexer by an alias.
docstring_tokens: Get a lexer by an alias .
function: def get_lexer_by_name(_alias, **options):
      """Get a lexer by an alias.
  
      Raises ClassNotFound if not found.
      """
      if not _alias:
          raise ClassNotFound('no lexer for alias %r found' % _alias)
  
      # lookup builtin lexers
      for module_name, name, aliases, _, _ in itervalues(LEXERS):
          if _alias.lower() in aliases:
              if name not in _lexer_cache:
                  _load_lexers(module_name)
              return _lexer_cache[name](**options)
      # continue with lexers from setuptools entrypoints
      for cls in find_plugin_lexers():
          if _alias.lower() in cls.aliases:
              return cls(**options)
      raise ClassNotFound('no lexer for alias %r found' % _alias)
function_tokens: def get_lexer_by_name ( _alias , * * options ) : if not _alias : raise ClassNotFound ( 'no lexer for alias %r found' % _alias ) # lookup builtin lexers for module_name , name , aliases , _ , _ in itervalues ( LEXERS ) : if _alias . lower ( ) in aliases : if name not in _lexer_cache : _load_lexers ( module_name ) return _lexer_cache [ name ] ( * * options ) # continue with lexers from setuptools entrypoints for cls in find_plugin_lexers ( ) : if _alias . lower ( ) in cls . aliases : return cls ( * * options ) raise ClassNotFound ( 'no lexer for alias %r found' % _alias )