Python help() built-in function
From the Python 3 documentation
Invoke the built-in help system. (This function is intended for interactive use.) If no argument is given, the interactive help system starts on the interpreter console. If the argument is a string, then the string is looked up as the name of a module, function, class, method, keyword, or documentation topic, and a help page is printed on the console.
Introduction
The help() function in Python is a built-in utility that provides access to Python’s extensive help system. It is particularly useful for interactive exploration and learning, as it allows you to get documentation for modules, functions, classes, and keywords directly in the Python interpreter. When called without an argument, it starts an interactive help session; otherwise, it prints help for the given object.
Examples
>>> help(type)
# Help on class type in module builtins:
# class type(object)
# | type(object_or_name, bases, dict)
# | type(object) -> the object's type
# | type(name, bases, dict) -> a new type
# |
# | Methods defined here:
# |
# | __call__(self, /, *args, **kwargs)
# | Call self as a function.
# |
# | __delattr__(self, name, /)
# | Implement delattr(self, name).
# |
# | __dir__(self, /)
# | Specialized __dir__ implementation for types.
# |
# | __getattribute__(self, name, /)
# :
>>> help(str)
# Help on class str in module builtins:
# class str(object)
# | str(object='') -> str
# | str(bytes_or_buffer[, encoding[, errors]]) -> str
# |
# | Create a new string object from the given object. If encoding or
# | errors is specified, then the object must expose a data buffer
# | that will be decoded using the given encoding and error handler.
# | Otherwise, returns the result of object.__str__() (if defined)
# | or repr(object).
# | encoding defaults to sys.getdefaultencoding().
# | errors defaults to 'strict'.
# |
# | Methods defined here:
# :
>>> help(help)
# Help on _Helper in module _sitebuiltins object:
# class _Helper(builtins.object)
# | Define the builtin 'help'.
# |
# | This is a wrapper around pydoc.help that provides a helpful message
# | when 'help' is typed at the Python interactive prompt.
# |
# | Calling help() at the Python prompt starts an interactive help session.
# | Calling help(thing) prints help for the python object 'thing'.
# |
# | Methods defined here:
# |
# | __call__(self, *args, **kwds)
# | Call self as a function.
# |
# :