Simple creation
Input
User('Alice', 30).age
Output
30
Constructing a User with a valid age returns that age from the age property.
Full lesson preview
Implement Validation in a Property Setter
Learn to enforce constraints using a property setter that validates assignments and raises ValueError for invalid data.
Python practice13 minEncapsulation & Access PatternsIntermediateLast updated April 8, 2026
Problem statement
Create a User class with a validated age property. The constructor should accept name and age. The age property must be an integer between 0 and 130 inclusive. If an invalid value is assigned to age (wrong type or out of range), the setter should raise a ValueError. Implement the age property (getter and setter) using Python's @property decorator and ensure the value is stored privately.
Task
Implement a class property setter that validates input types and ranges, preventing invalid state.
Examples
Input format
A class User(name: str, age: int). Tests will create instances and access or set the age property in a single-expression form.
Output format
Accessing .age should return the numeric age (as int).
Constraints
age must be an integer (not bool) and satisfy 0 <= age <= 130. On invalid assignment, raise ValueError. Use a private attribute to store the age (e.g., self._age).
Samples
Sample 1
Input
User('Bob', 25).age
Output
25
25 is within the allowed range and is an integer.