> ## Documentation Index
> Fetch the complete documentation index at: https://bazel-flags-doc.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# list

The built-in list type. Example list expressions:

```
x = [1, 2, 3]
```

Accessing elements is possible using indexing (starts from `0`):

```
e = x[1]   # e == 2
```

Lists support the `+` operator to concatenate two lists. Example:

```
x = [1, 2] + [3, 4]   # x == [1, 2, 3, 4]
x = ["a", "b"]
x += ["c"]            # x == ["a", "b", "c"]
```

Similar to strings, lists support slice operations:

```
['a', 'b', 'c', 'd'][1:3]   # ['b', 'c']
['a', 'b', 'c', 'd'][::2]  # ['a', 'c']
['a', 'b', 'c', 'd'][3:0:-1]  # ['d', 'c', 'b']
```

Lists are mutable, as in Python.

## Members

* [append](#append)
* [clear](#clear)
* [extend](#extend)
* [index](#index)
* [insert](#insert)
* [pop](#pop)
* [remove](#remove)

## append

```
None list.append(item)
```

Adds an item to the end of the list.

### Parameters

ParameterDescription`item`
required

Item to add at the end.

## clear

```
None list.clear()
```

Removes all the elements of the list.

## extend

```
None list.extend(items)
```

Adds all items to the end of the list.

### Parameters

ParameterDescription`items`
iterable;
required

Items to add at the end.

## index

```
int list.index(x, start=unbound, end=unbound)
```

Returns the index in the list of the first item whose value is x. It is an error if there is no such item.

### Parameters

ParameterDescription`x`
required

The object to search.
`start`[int](../core/int.html);
default is `unbound`

The start index of the list portion to inspect.
`end`[int](../core/int.html);
default is `unbound`

The end index of the list portion to inspect.

## insert

```
None list.insert(index, item)
```

Inserts an item at a given position.

### Parameters

ParameterDescription`index`[int](../core/int.html);
required

The index of the given position.
`item`
required

The item.

## pop

```
unknown list.pop(i=-1)
```

Removes the item at the given position in the list, and returns it. If no `index` is specified, it removes and returns the last item in the list.

### Parameters

ParameterDescription`i`[int](../core/int.html);
default is `-1`

The index of the item.

## remove

```
None list.remove(x)
```

Removes the first item from the list whose value is x. It is an error if there is no such item.

### Parameters

ParameterDescription`x`
required

The object to remove.