122     known_paths = set()
128         if dircase not in known_paths:
130             known_paths.add(dircase)
132     return known_paths
148 def addpackage(sitedir, name, known_paths):  argument
153     if known_paths is None:
154         known_paths = _init_pathinfo()
173                 if not dircase in known_paths and os.path.exists(dir):
175                     known_paths.add(dircase)
186         known_paths = None
187     return known_paths
190 def addsitedir(sitedir, known_paths=None):  argument
193     if known_paths is None:
194         known_paths = _init_pathinfo()
199     if not sitedircase in known_paths:
201         known_paths.add(sitedircase)
208         addpackage(sitedir, name, known_paths)
210         known_paths = None
211     return known_paths
305 def addusersitepackages(known_paths):  argument
316         addsitedir(user_site, known_paths)
317     return known_paths
355 def addsitepackages(known_paths, prefixes=None):  argument
359             addsitedir(sitedir, known_paths)
361     return known_paths
465 def venv(known_paths):  argument
504         addsitepackages(known_paths, [sys.prefix])
514     return known_paths
566     known_paths = removeduppaths()
572     known_paths = venv(known_paths)
575     known_paths = addusersitepackages(known_paths)
576     known_paths = addsitepackages(known_paths)