In Python, `init` and `self` are related to object-oriented programming and are commonly used when defining classes. They are not standalone functions or keywords; rather, they have specific roles within class definitions:
1. `__init__` (Double Underscore Init):
- `__init__` is a special method (also called a constructor) in Python classes.
- It is automatically called when an object of the class is created (instantiated).
- The primary purpose of `__init__` is to initialize the attributes (variables) of the object.
- You can think of it as the class's "initializer" or "constructor."
- `__init__` takes at least one parameter, conventionally named `self`, which refers to the instance of the class being created. You can also define additional parameters to initialize the object's attributes.
Example:
```python
class MyClass:
def __init__(self, value):
self.value = value
# Creating an object of MyClass
obj = MyClass(42)
```
2. `self`:
- `self` is a conventionally used name for the first parameter of instance methods in Python classes. You can actually name it something else, but using `self` is a widely accepted convention.
- It represents the instance of the class itself and allows you to access and manipulate its attributes and methods.
- By convention, `self` is passed as the first parameter to all instance methods, including `__init__`, but you don't need to explicitly pass it when calling the method; Python does that for you.
Example:
```python
class MyClass:
def __init__(self, value):
self.value = value
def print_value(self):
print(self.value)
obj = MyClass(42)
obj.print_value() # This implicitly passes 'obj' as 'self' to print_value()
```
In the example above, `self` is used within the `__init__` method to assign the `value` parameter to an attribute of the object, and it's also used within the `print_value` method to access the object's `value` attribute.
Understanding `__init__` and `self` is fundamental to working with classes and objects in Python, as they allow you to create objects with initialized attributes and define methods that can operate on those attributes.
