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5: Advanced Functions
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Summary
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- You can call functions using parameters as keyword parameters or positional parameters
- Python allows you to set defaults for parameters
- You can force parameters yo be positional only or keyword only using / and *
- Specifying *name is a way of using a variable number  of positional parameters 
    - Any arguments supplied that are not used by positional parameters are stored in *name asa  tuple
- Specifying **kwname works in the same way as *name but any unused keyword arguments are stored in it as a  dictionary
- You can pass parameters as tuples or dictionaries by using the unpacking operators * and **
- Functions can return multiple values by returning a tuple which czn be unpacked into variables using destructuring assignment
- Docstrings can be used to create rudimentary documentation for a function
- Annotations can be applied to parameters and return values, usually to indicate the type

Program
============

.. literalinclude:: programs/chapterFive.py
   :language: python

Program Output
=================

.. code-block:: console
    
    (docs-env) root@BMitchellLTOP:~/git/sphinx_students/source/programming_lang/book/programs# python3 chapterFive.py
    Extras received (stored as dictionary): {'gift_wrap': True}
    Subtotal: 40.0
    Total: 40.0
    Numbers received (stored as tuple): (1, 2, 3)
    Sum: 6
    Extras received (stored as dictionary): {}
    Second Total: 47.25