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Python FTW: Under the Hood

Quick Recap

Understand Python's variable scope rules, the behavior of mutable objects, and important pitfalls in exception handling and loop variables. Learn how to properly use global and nonlocal keywords, handle mutable defaults, and grasp the effects of list multiplication and name mangling. This lesson helps you avoid common errors and improve your Python coding skills through practical insights and best practices.

We'll cover the following...
  • An assignment to a global variable in a local scope creates a new variable in the local scope. To actually modify the variable outside the local scope, you’ll have to use either the global or the nonlocal keyword.
  • Multiplication of lists containing mutable items creates multiple references to the same mutable object under the hood.
  • The del x keyword’s behavior is to decrease the reference count of x, and the dunder method __del__ is only invoked by Python when the object’s reference count reaches zero.
  • In an interactive
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