Classes and Objects

• Objects are an encapsulation of variables and functions into a single entity.

• Classes are essentially a template to create your objects.

• Objects get their variables and functions from classes.

• Example Class

  class MyClass: variable = “blah”

  def function(self): print(“This is a message inside the class.”)

• Notes:
  • self in Python is equivalent to this in JavaScript
  • class in Python is equivalent to the Constructor(blueprint) in JavaScript
  • variable in Python is equivalent to the property in JavaScript (accessed through dot)
  • function in Python is equivalent to the method in JavaScript (accessed through dot)

Thinking Recursively in Python

• In order to solve any probelm, the problem should be broken down into smaller elements.
• Iterative Algorithm built on an explicit loop construction
  • Example:

    houses = [“Eric’s house”, “Kenny’s house”, “Kyle’s house”, “Stan’s house”]

    def deliver_presents_iteratively(): for house in houses: print(“Delivering presents to”, house)

• Anything that can be defined in terms of smaller entities is recursive

recursive functions

• Definition:

  A recursive function is a function defined in terms of itself via self-referential expressions.

• Structure:
  • base case
  • recursive case

Maintaining State

• Thread the state through each recursive call so that the current state is part of the current call’s execution context

• Keep the state in global scope

recursive data structures

• A data structure is recursive if it can be defined in terms of a smaller version of itself.

• list, set, tree, dictionary, e are recursive data structures

Python Testing | pytest

• pytest : a library for testing Python code

Fixtures

• In pytest, you define fixtures using a combination of the pytest.fixture decorator, along with a function definition

Coverage

• Now, 100% code coverage doesn’t mean that your code is perfect or that it lacks bugs. But it does give you a greater degree of confidence in the code and the fact that it has been run at least once.