# Python Operator Module

The `operator` module exports a set of efficient functions corresponding to the intrinsic operators of Python. For example, `operator.add(x, y)` is equivalent to the expression `x + y`.

## Importing the Module

```python
import operator
```

## Arithmetic Operators

The module provides functions for standard arithmetic operations.

*   `operator.add(a, b)`: `a + b`
*   `operator.sub(a, b)`: `a - b`
*   `operator.mul(a, b)`: `a * b`
*   `operator.truediv(a, b)`: `a / b`
*   `operator.floordiv(a, b)`: `a // b`
*   `operator.mod(a, b)`: `a % b`
*   `operator.pow(a, b)`: `a ** b`

```python
import operator

a = 10
b = 3

print(operator.add(a, b))      # Output: 13
print(operator.floordiv(a, b)) # Output: 3
```

## Comparison Operators

*   `operator.lt(a, b)`: `a < b`
*   `operator.le(a, b)`: `a <= b`
*   `operator.eq(a, b)`: `a == b`
*   `operator.ne(a, b)`: `a != b`
*   `operator.ge(a, b)`: `a >= b`
*   `operator.gt(a, b)`: `a > b`

```python
import operator

x = 5
y = 10

print(operator.lt(x, y)) # Output: True
```

## Higher-Order Functions

The `operator` module provides tools for functional programming, often used with `map()`, `sorted()`, `itertools.groupby()`, etc.

### `itemgetter`

Return a callable object that fetches item from its operand using the operand’s `__getitem__()` method.

```python
import operator

data = [('apple', 3), ('banana', 2), ('pear', 5)]

# Sort by the second element (count)
data.sort(key=operator.itemgetter(1))
print(data)
# Output: [('banana', 2), ('apple', 3), ('pear', 5)]
```

### `attrgetter`

Return a callable object that fetches attribute from its operand.

```python
import operator

class User:
    def __init__(self, name, id):
        self.name = name
        self.id = id
    def __repr__(self):
        return f"User({self.name})"

users = [User('Alice', 2), User('Bob', 1)]

# Sort by id
users.sort(key=operator.attrgetter('id'))
print(users)
# Output: [User(Bob), User(Alice)]
```

### `methodcaller`

Return a callable object that calls the method name on its operand.

```python
import operator

s = "hello world"
up = operator.methodcaller('upper')
print(up(s)) # Output: HELLO WORLD
```

[[programming/python/python]]