Dictionaries
============ 
.. raw:: html

    <iframe width="560" height="315" src="https://www.youtube.com/embed/qq5054jqU40" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


Creating a dictionary
---------------------
.. code-block:: python

    # create empty dict (two ways)
    empty_dict = {}
    empty_dict = dict()

    # Create pre-filled dict
    some_dict = {"key1": "value1", "key2": "value2"}

    # more readable formatting (expecially for lots of key/value pairs)
    player = {
        "health": 100,
        "name": "Frankie",
        "class": "Wizard",
    }

Accessing a value in a dictionary
---------------------------------
Similar to a list, instead of accessing the value by the index, you access it using the key (label) you defined::

    player = {
        "health": 100,
        "name": "Frankie",
        "class": "Wizard",
    }

    print(player["health"])  # outputs 100

.. warning:: When using dictionaries in f-strings, you cannot use the same quote types.

.. code-block:: python

    print(f"Health: {player["health"]}")  # WON'T WORK
    print(f"Health: {player['health']}")  # works


Adding a value to a dictionary
------------------------------
.. code-block:: python
    :emphasize-lines: 7

    player = {
        "health": 100,
        "name": "Frankie",
        "class": "Wizard",
    }

    player["strength"] = 50  # adds key/value strength: 50
    print(player["strength"])


Modifying a value in a dictionary
---------------------------------
.. code-block:: python
    :emphasize-lines: 7

    player = {
        "health": 100,
        "name": "Frankie",
        "class": "Wizard",
    }

    player["health"] = 90  # changes health to 90
    print(player["health"])
    
    player["health"] += 10  # increases health back to 100
    print(player["health"])


Removing a value from a dictionary
----------------------------------
.. code-block:: python
    :emphasize-lines: 8

    player = {
        "health": 100,
        "name": "Frankie",
        "class": "Wizard",
        "not-needed": "Then why is it here?"
    }

    del player["not-needed"]
    print(player["not_needed"])  # raises KeyError (key doesn't exist anymore)


Iterating through dictionary keys
---------------------------------
The ``.keys()`` method will return a collection of all the dictionary's keys.

.. code-block:: python

    player = {
        "health": 100,
        "name": "Frankie",
        "class": "Wizard",
    }

    for key in player.keys():
        print(key)

    """outputs:
    health
    name
    class
    """


Iterating through dictionary values
-----------------------------------

The ``.values()`` method will return a collection of all the dictionary's values.

.. code-block:: python

    player = {
        "health": 100,
        "name": "Frankie",
        "class": "Wizard",
    }

    for value in player.values():
        print(value)

    """outputs:
    100
    Frankie
    Wizard
    """

Iterating through dictionary keys and values
--------------------------------------------
The ``.items()`` method will return a collection of all the dictionary's keys and values paired together. In our example, it would be equivalent to the folling list::

    [("health", 100), ("name", "Frankie"), ("class", "Wizard")]

Essentially, a collection of tuples. FOr this, you will need two loop variables: `key` and `value`.

.. code-block:: python

    player = {
        "health": 100,
        "name": "Frankie",
        "class": "Wizard",
    }

    for key, value in player.items():
        print(key, value)

    """outputs:
    health 100
    name Frankie
    class Wizard
    """