# Dunder Methods — Python

Source: https://www.geekswithgeeks.com/en/python/py-dunder-methods

> Double-underscore methods let your objects work with built-in operators and functions.

## __str__ and __repr__

`__str__` controls `print(obj)` / `str(obj)`; `__repr__` is the developer-facing representation seen in the REPL.

```python
class Point:
    def __init__(self, x, y):
        self.x, self.y = x, y
    def __str__(self):
        return f"({self.x}, {self.y})"
    def __repr__(self):
        return f"Point(x={self.x}, y={self.y})"

p = Point(2, 3)
print(p)        # (2, 3)  -- uses __str__
print([p])      # [Point(x=2, y=3)] -- uses __repr__
```

## __eq__

`__eq__` defines what `==` means for your objects — without it, two "equal-looking" objects compare unequal by identity.

```python
class Point:
    def __init__(self, x, y):
        self.x, self.y = x, y
    def __eq__(self, other):
        return self.x == other.x and self.y == other.y

print(Point(1, 2) == Point(1, 2))  # True
```