parameters: (cls, options)
return_statement: return index_urls or None
docstring: Return a list of index urls from user-provided options.
docstring_summary: Return a list of index urls from user-provided options.
docstring_tokens: Return a list of index urls from user - provided options .
function: def _get_index_urls(cls, options):
          # type: (Values) -> Optional[List[str]]
          """Return a list of index urls from user-provided options."""
          index_urls = []
          if not getattr(options, "no_index", False):
              url = getattr(options, "index_url", None)
              if url:
                  index_urls.append(url)
          urls = getattr(options, "extra_index_urls", None)
          if urls:
              index_urls.extend(urls)
          # Return None rather than an empty list
          return index_urls or None
function_tokens: def _get_index_urls ( cls , options ) : # type: (Values) -> Optional[List[str]] index_urls = [ ] if not getattr ( options , "no_index" , False ) : url = getattr ( options , "index_url" , None ) if url : index_urls . append ( url ) urls = getattr ( options , "extra_index_urls" , None ) if urls : index_urls . extend ( urls ) # Return None rather than an empty list return index_urls or None