reading-notes

Testing and Modules

TDD - Test-Driven Development is a strategy to write tests first.
Things to consider when writing tests:
- The test name should be descriptive and say what is expected and what we are testing.
- Arrange - you need to organize the data needed to execute that piece of code (input)
- Act - here you will execute the code being tested (exercise the behavior)
- Assert - after executing the code, you will check if the result (output) is the same as you were expecting.
The cycle:
- Write a unit test and make it fail
- Write the feature and make the test pass
- Refactor the code — the first version doesn’t need to be the beautiful one
The greatest advantage about TDD is to craft the software design first
Your code will be more reliable: after a change you can run your tests and be in peace.

If the python interpreter is running that module (the source file) as the main program, it sets the special name variable to have a value “main”.
If this file is being imported from another module, name will be set to the module’s name. Module’s name is available as value to name global variable.

Recursion - The process in which a function calls itself directly or indirectly. The corresponding function is called a recursive function.
Recursion can reduce the length of our code and make it easier to read and write.
Properties of recursion:
- Performing the same operations multiple times with different inputs.
- In every step, we try smaller inputs to make the problem smaller.
- Base condition is needed to stop the recursion otherwise infinite loop will occur.
If the base case is not reached or not defined, then the stack overflow problem may arise.
A function is called direct recursive if it calls the same function.
A function is called indirect recursive if it calls another function directly or indirectly.