dir() in particular is extremely useful for inspecting unknown objects, modules, or classes. If you need to filter out the default attributes, and clarify the output, you can filter the output this way:

>>> [att for att in dir(dictionary) if not att.startswith('__')]
['clear', 'copy', 'fromkeys', 'get', 'items', 'keys', 'pop', 'popitem', 'setdefault', 'update', 'values']

In the same way, if you're searching for a particular method (such as something that starts with set), you can filter in the same way.

help() will display the docstring of a function or class. docstring is the string defined just after the definition to document the function or class:

>>> def something():
...     '''
...     This is help for something
...     '''
...     pass
...
>>> help(something)
Help on function something in module __main__:

something()
    This is help for something

Notice how in the next example, the  This is help for something string is defined just after the definition of the function.

The documentation for the built-in functions can be found at https://docs.python.org/3/library/functions.html#built-in-functions, and the full documentation for pprint can be found at https://docs.python.org/3/library/pprint.html#.