You want to create a class Student that stores name and grades list. Which __init__ method correctly initializes these attributes?
hard🚀 Application Q8 of Q15
Python - Constructors and Object Initialization
You want to create a class Student that stores name and grades list. Which __init__ method correctly initializes these attributes?
Adef __init__(self, name, grades=None):
self.name = name
self.grades = grades or []
Bdef __init__(self, name, grades):
self.name = name
self.grades = grades
Cdef __init__(self, name, grades=[]):
self.name = name
self.grades = grades
Ddef __init__(self, name):
self.name = name
self.grades = []
Step-by-Step Solution
Solution:
Step 1: Understand mutable default arguments
Using a mutable default like [] directly can cause shared state across objects.
Step 2: Analyze each option
def __init__(self, name, grades=None):
self.name = name
self.grades = grades or [] uses None default and assigns a new list inside, avoiding shared mutable defaults.
Final Answer:
def __init__(self, name, grades=None):
self.name = name
self.grades = grades or [] -> Option A
Quick Check:
Avoid mutable defaults; use None and assign inside = B [OK]
Quick Trick:Never use mutable objects as default parameters [OK]
Common Mistakes:
MISTAKES
Using empty list as default parameter directly
Not initializing mutable attributes properly
Causing shared data between instances
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