code: def find_on_path(importer, path_item, only=False):
      
      path_item = _normalize_cached(path_item)
  
      if _is_unpacked_egg(path_item):
          yield Distribution.from_filename(
              path_item, metadata=PathMetadata(
                  path_item, os.path.join(path_item, 'EGG-INFO')
              )
          )
          return
  
      entries = safe_listdir(path_item)
  
      # for performance, before sorting by version,
      # screen entries for only those that will yield
      # distributions
      filtered = (
          entry
          for entry in entries
          if dist_factory(path_item, entry, only)
      )
  
      # scan for .egg and .egg-info in directory
      path_item_entries = _by_version_descending(filtered)
      for entry in path_item_entries:
          fullpath = os.path.join(path_item, entry)
          factory = dist_factory(path_item, entry, only)
          for dist in factory(fullpath):
              yield dist
docs: Yield distributions accessible on a sys.path directory