`setattr()`

The built-in setattr() function allows you to set the value of an attribute of an object dynamically at runtime using the attribute’s name as a string. This is particularly useful when you don’t know the attribute names in advance:

>>> class Person:
...     def __init__(self, name, age):
...         self.name = name
...         self.age = age
...

>>> jane = Person("Jane", 25)
>>> setattr(jane, "age", 26)
>>> jane.age
26

`setattr()` Signature

setattr(object, name, value)

Arguments

Argument	Description
`object`	The object whose attribute you want to set.
`name`	A string representing the name of the attribute to set.
`value`	The new value you want to assign to the specified attribute.

Return Value

The setattr() function doesn’t return a fruitful value. Instead, it modifies the input object by setting the specified attribute to the given value.

`setattr()` Examples

With a class instance as an argument:

>>> class Car:
...     def __init__(self, make, model):
...         self.make = make
...         self.model = model
...

>>> toyota = Car("Toyota", "Corolla")
>>> setattr(toyota, "year", 2020)
>>> toyota.year
2020

`setattr()` Common Use Cases

The most common use cases for setattr() include:

Dynamically setting attributes when the attribute names are determined at runtime
Modifying attributes of objects in a generic way, such as within a loop
Implementing frameworks or libraries that require flexible attribute management

`setattr()` Real-World Example

Suppose you have a scenario where you need to update multiple attributes of an object based on a dictionary of key-value pairs. You can use setattr() to achieve this dynamically.

>>> class Book:
...     def __init__(self, title, author, year):
...         self.title = title
...         self.author = author
...         self.year = year
...

>>> book = Book("1984", "George Orwell", 1949)
>>> updates = {"title": "Animal Farm", "year": 1945}
>>> for attr, value in updates.items():
...     setattr(book, attr, value)
...
>>> book.title
'Animal Farm'
>>> book.year
1945

In this example, setattr() helps update the book object’s attributes based on the provided dictionary, allowing for flexible and dynamic attribute management.