The original title is: "Class vs Instance Variables: The Mutation Trap That Catches Experienced Developers"

Short summary

A Python tutorial explaining the classic class variable mutation trap where mutable class attributes are shared across all instances. Moving initialization to __init__ creates per-instance state. Immutable types like integers behave differently with +=, creating instance variables that shadow the class variable. The article ends with a pitch for a Python interview practice platform.

• •Mutable class variables (like lists) are shared across all instances — appending affects every object
• •Moving initialization to __init__ creates fresh per-instance state
• •Immutable types with += create instance variables that shadow the class variable without mutating it

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