# Python Array Module

The `array` module defines an object type which can efficiently represent an array of basic values: characters, integers, floating point numbers. Arrays are sequence types and behave very much like lists, except that the type of objects stored in them is constrained.

## Importing the Module

```python
import array
```

## Creating Arrays

To create an array, you need to specify a type code (a single character) that defines the type of the elements.

### Common Type Codes

| Type Code | C Type | Python Type | Minimum Size in Bytes |
| :--- | :--- | :--- | :--- |
| `'b'` | signed char | int | 1 |
| `'B'` | unsigned char | int | 1 |
| `'h'` | signed short | int | 2 |
| `'H'` | unsigned short | int | 2 |
| `'i'` | signed int | int | 2 |
| `'I'` | unsigned int | int | 2 |
| `'l'` | signed long | int | 4 |
| `'L'` | unsigned long | int | 4 |
| `'f'` | float | float | 4 |
| `'d'` | double | float | 8 |

### Example

```python
import array

# Create an array of integers (signed int)
a = array.array('i', [1, 2, 3, 4, 5])
print(a)
# Output: array('i', [1, 2, 3, 4, 5])
```

## Basic Operations

Arrays support standard sequence operations like indexing, slicing, concatenation, and multiplication.

```python
print(a[0])      # Output: 1
print(a[1:3])    # Output: array('i', [2, 3])
```

## Methods

### `append()`

Append a new item to the end of the array.

```python
a.append(6)
print(a)
```

### `extend()`

Append items from an iterable to the end of the array.

```python
a.extend([7, 8, 9])
print(a)
```

### `insert()`

Insert a new item into the array at a given position.

```python
a.insert(0, 0)
print(a)
```

### `remove()`

Remove the first occurrence of a value from the array.

```python
a.remove(0)
print(a)
```

### `tolist()`

Convert the array to an ordinary list with the same items.

```python
l = a.tolist()
print(l)
```

[[programming/python/python]]