## About

Initialization and extraction of variables

## Articles Related

## List

Unpacking: A convenient way to initialize variables from a list

```
>>> [x,y] = [1, 2]
>>> x
1
>>> y
2
```

## Sequence

Multiple assignment is really just a combination of tuple packing and sequence unpacking

### Packing

Sequence packing: The values 12345, 54321 and 'hello!' are packed together in a tuple

```
t = 12345, 54321, 'hello!'
t
```

```
(12345, 54321, 'hello!')
```

### Unpacking

The reverse packing operation

`x, y, z = t`

```
>>> x
12345
>>> y
54321
>>> z
'hello!'
```

Sequence unpacking works for any sequence on the right-hand side. Sequence unpacking requires the list of variables on the left to have the same number of elements as the length of the sequence.

## Comprehension

```
>>> listoflists = [[1,1],[2,4],[3, 9]]
>>> [y for [x,y] in listoflists]
[1, 4, 9]
```