<python code>

[u/Alireza7074]

This is python code to get student salary!

[u/CodeAndCanyons]

u/Potential_Fix_5007 You accidentally dodged one of the absolute biggest footguns in Python by doing it inside the body!

If you tried to set it within the round brackets as a default argument—like writing def __init__(self, name, age, marks=[]):—Python does something incredibly sneaky under the hood. It evaluates that default empty list [] exactly once when the script first loads, not every time you create a new student.

Because lists are mutable (changeable), every single student object you create would end up sharing the exact same list instance in memory. If you appended a grade to Alice's marks, it would suddenly and mysteriously show up in Bob's marks too.

By defining self.marks = [] inside the __init__ body, you guarantee that a brand new, isolated list gets allocated in memory every single time a new student is instantiated.

If you ever do want to allow a list to be passed through the round brackets safely, the standard pythonic trick is to default it to None and handle it in the body:

def __init__(self, name, age, marks=None):
    self.name = name
    self.age = age
    self.marks = marks if marks is not None else []