>help('sys')

>help('str')

>a = [1,2,3]
>help(a)

>help(a.append)

> help('dir')
Help on built-in function dir in module builtins:
dir(...)
  dir([object]) -> list of strings

  If called without an argument, return the names in the current scope.
  Else, return an alphabetized list of names comprising (some of) the attribut
es
  of the given object, and of attributes reachable from it.
  If the object supplies a method named __dir__, it will be used; otherwise
  the default dir() logic is used and returns:
   for a module object: the module's attributes.
   for a class object: its attributes, and recursively the attributes
    of its bases.
   for any other object: its attributes, its class's attributes, and
    recursively the attributes of its class's base classes.