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Earlier in the course, we looked at
two of the data structures

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that are built into python. We saw
how to use lists and tuples,

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and discussed some of the differences
between them. In this section, we're going

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to learn about two more
built-in data structures:

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dictionaries and sets. lists
and tuples are sequence types.

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That means we can use indexing
to access individual items.

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dictionaries and sets
aren't sequences - we can't

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access the items using index positions.
When dealing with items in a dictionary,

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we use a key to get individual
values from the dictionary.

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dictionaries store key/value pairs.
You'll also find a dictionary referred

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to as a mapping, and if you
know java then a python dict

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is equivalent to a java hashmap.
A set is an unordered

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collection of things.
There's no way to retrieve a specific

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item from a set, which can
be confusing, but sets can be

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very useful, as we'll see.

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So for this section, I'm
going to create a new project,

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and we'll call this one
DictAndSet.

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We've done this a few times now.
Choose Python, on the left hand side,

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and choose a project sdk in the drop
down - the top at the right there -

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and then click on Next.
Then type in the project name,

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which I mentioned was DictAndSet.

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Click on Finish.

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Alright, so we'll start the section
with dictionaries in the next video.