Description Python setattr()

Python setattr()

The setattr() method sets the value of given attribute of an object.

The syntax of setattr() method is:
setattr(object, name, value)If you want to get an attribute of an object, use getattr().

setattr() Parameters

The setattr() method takes three parameters:
• object - object whose attribute has to be set
• name - string which contains the name of the attribute to be set
• value - value of the attribute to be set

Return value from setattr()

The setattr() method returns None.

Example 1: How setattr() works in Python?

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class Person:
name = 'Adam'

p = Person()
print('Before modification:', p.name)

# setting name to 'John'
setattr(p, 'name', 'John')

print('After modification:', p.name)
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When you run the program, the output will be:
Before modification: Adam
After modification: John

Example 2: setattr() when named attribute is not found and setting attribute to None

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If the attribute is not found, setattr() creates a new attribute by the given name and value.
However, this is only possible if the object implements __dict__() method.
You can check if it does by using dir() method.
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class Person:
name = 'Adam'

p = Person()

# setting attribute name to None
setattr(p, 'name', None)
print('Name is:', p.name)

# setting an attribute not present
# in Person
setattr(p, 'age', 23)
print('Age is:', p.age)
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When you run the program, the output will be:
Name is: None
Age is: 23