docs: def load_stdlib():
      '''Scans sys.path for standard library modules.
      '''
      if _stdlib:
          return _stdlib
  
      prefixes = tuple({os.path.abspath(p) for p in (
          sys.prefix,
          getattr(sys, 'real_prefix', sys.prefix),
          getattr(sys, 'base_prefix', sys.prefix),
      )})
  
      for sp in sys.path:
          if not sp:
              continue
          _import_paths.append(os.path.abspath(sp))
  
      stdpaths = tuple({p for p in _import_paths
                        if p.startswith(prefixes) and 'site-packages' not in p})
  
      _stdlib.update(sys.builtin_module_names)
  
      for stdpath in stdpaths:
          if not os.path.isdir(stdpath):
              continue
  
          for item in os.listdir(stdpath):
              if item.startswith('.') or item == 'site-packages':
                  continue
  
              p = os.path.join(stdpath, item)
              if not os.path.isdir(p) and not item.endswith(('.py', '.so')):
                  continue
  
              _stdlib.add(item.split('.', 1)[0])
  
      return _stdlib