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L5: Advanced Functions
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Overview
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This lecture explores advanced function concepts in Python, building on the fundamentals from L4. You will learn about programming paradigms (procedural, functional, object-oriented), first-class functions, lambda expressions, closures, callables, decorators, and partial functions. These concepts are essential for writing clean, reusable, and composable Python code and form the foundation for object-oriented programming in later lectures.


.. admonition:: Learning Objectives
   :class: learning-objectives

   By the end of this lecture, you will be able to:

   - Distinguish imperative, functional, and object-oriented programming paradigms.
   - Use functions as first-class objects: assign, pass, and return them.
   - Write anonymous functions with ``lambda`` and understand their limitations.
   - Explain closures and how inner functions capture enclosing state.
   - Make objects callable with the ``__call__`` dunder method.
   - Write and apply decorators to extend function behavior.
   - Stack multiple decorators and preserve function metadata with ``functools.wraps``.
   - Create partial functions using ``functools.partial``.
   - Use built-in higher-order functions: ``map``, ``filter``, and ``sorted`` with ``key``.


.. toctree::
   :maxdepth: 2
   :titlesonly:
   :hidden:

   l5_lecture
   l5_exercises
   l5_quiz
   l5_references

Next Steps
----------

- In the next lecture, we will cover Object-Oriented Programming I:

  - Classes and objects
  - Attributes and methods
  - Constructors and ``__init__``
  - Encapsulation and properties
  - Dunder methods

- Review and experiment with all code snippets and exercises from today's lecture.
- Practice writing decorators and closures.
- Read `Real Python: Python Classes <https://realpython.com/python-classes/>`_.