Review: Triangular Number Sequence

[ajfumero8]

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name: solution review
about: A template PR for code review with a checklist

For Triangular Number Sequence Challenge

Write a function that defines the triangular number sequence with a formula and input ability in order to insert several different integer inputs for each triangle in the sequence

The triangle sequence goes as follows:

1, 3, 6, 10, 15 

It is a formula of n(n+1)/2 where n is any given number in the sequence (easier read as {1+2+3+4...})
If you wanted to check for the 5th number of the sequence, it would look like 5(5+1)/2 = 15
Ex. Code

triangle(1) ➞ 1

triangle(6) ➞ 21

triangle(215) ➞ 23220

Files

• The file name describes the function's behavior
• There is a module docstring in the function file
• The test file's name matches the function file name -
  /tests/test_file_name.py
• There is a module docstring in the tests file

Unit Tests

• The test class has a helpful name in PascalCase
• The test class has a docstring
• Every unit test has
  • A helpful name
  • A clear docstring
  • Only one assertion
  • There is no logic in the unit test
• All tests pass
• There are tests for defensive assertions
• There are tests for boundary cases

Function Docstring

• The function's behavior is described
• The function's arguments are described:
  • Type
  • Purpose
  • Other assumptions (eg. if it's a number, what's the expected range?)
• The return value is described
  • Type
  • Other assumptions are documented
• The defensive assertions are documented using Raises:
  • Each assumption about an argument is checked with an assertion
  • Each assertion checks for only one assumption about the argument
• Include 3 or more (passing!) doctests

The Function

• The function's name describes it's behavior
• The function's name matches the file name
• The function has correct type annotations
• The function is not called in the function file

Strategy

Do's

• Variable names help to understand the strategy
• Any comments are clear and describe the strategy
• Lines of code are spaced to help show different stages of the strategy

Don'ts

• The function's strategy is not described in the documentation
• Comments explain the strategy, not the implementation
• The function does not have more comments than code
  • If it does, consider finding a new strategy or a simpler implementation

Implementation

• The code passes the formatting checks
• The code passes all Ruff linting checks
• The code has no (reasonable) Pylint errors
  • In code review, you can decide when fixing a Pylint error is helpful and
    when it's too restricting.
• Variables are named with snake_case
• Variable names are clear and helpful
• The code follows the strategy as simply as possible
• The implementation is as simple as possible given the strategy
• There are no commented lines of code
• The code includes defensive assertions
• Defensive assertions include as little logic as possible