Lists (Part 1)

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class: center, middle

# Lists (Part 1)

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## Lists As Ordered Collections

Like strings, lists are a **collection data type**

This also means they are non-primitive, or that they contain other data types

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## List Values

A list may contain _any_ value. Really. ANY value.

This means we can do things like:

```python
mixed_list = [1, 2, [3, 4]]
```

Here, `[3, 4]` is referred to as a **sublist**

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## Stuff We Can Do With Lists

### Get the length

```python
print(len(['a', 'b', 'c']))

mixed_list = [1, 2, [3, 4]]
print(len(mixed_list))
```

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## Stuff We Can Do With Lists

List with strings, we can access elements of a list directly using **bracket notation**

```python
some_letters = ['a', 'b', 'c']
print(some_letters[1])
```

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## List Membership

The `in` operator allows us to create boolean expressions that we can use to determine whether or not an item is in a list

```python
some_letters = ['a', 'b', 'c']

print('a' in some_letters)
print('d' in some_letters)
print('d' not in some_letters)
print(not 'd' in some_letters)
```

**Output**:
`True`

`False`

`True`

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## Concatenation

Like strings, we can use `+` to concatenate lists

```python
combined = ['a', 'b', 'c'] + [1, 2, 3]
print(combined)
```

**Output:**
`['a', 'b', 'c', 1, 2, 3]`

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## Repetition

Similarly, we can use `*` to repeat lists

```python
repeated = [1, 2, 3] * 3
print(repeated)
```

**Output:**
[1, 2, 3, 1, 2, 3, 1, 2, 3]