algorithms

What about create a design pattern directory with the most popular design patterns examples?
We can create some rules like: have to be an explanation about the design pattern, the structure and one real world example.
The directory can be:

(folder) Design Patterns
-- (folder) Abstract Factory
-- -- AbstractFactory.js
-- -- AbstractFactoryTest.js
-- -- REAME.md

I can send some :

Describe your issue.

The docstring for factorial2 says:

If n < 0, the return value is 0.

However directly below that in the code, we can see this is not the case for n==-1

if exact:
    if n < -1:
        return 0
    if n <= 0:
        return 1

This

Let's make the error message more actionable.

Error user sees:

I would recommend adding similar named column(s):

- $"Provided {columnPurpose} column '{columnName}' not found in training data."
+ $"Provided {columnPurpose} column '{columnName}' not found in training