project-2.qmd

---
title: "Programming Project 2"
---

```{r}
#| echo: false
#| message: false
#| warning: false
library(tidyverse)
library(readxl)
assignments <- read_excel("assessment_schedule.xlsx") %>% 
  mutate(formatted_date = format(due_date, "%A, %B %d, %Y"))
```

Programming Projects are to be submitted to [gradescope](https://www.gradescope.com/courses/934148).

**Due date: `r assignments %>% filter(assessment == "Programming Project 2") %>% pull(formatted_date)` at 9pm**

In this programming project you will implement a number of Python functions to validate or transform values conditionally. Make sure you follow the provided [style guide](style.html) (you will be graded on it!). You are allowed to use `round()`, `str()` and `len()`, but other than that you are **not** allowed to use any other built-in method or function from any Python library.

Also make sure you check the [Academic Integrity](academic-integrity.html) and [Common Gradescope Errors](gradescope-errors.html) pages.

Name the program `grades.py`. Make sure that gradescope gives you the points for passing the test cases.

## `letter_grade()`

This function determines a letter grade ("A", "B", and so on) based on a float argument representing a percentage grade.

It returns a letter grade based on the following rules:

    -   Greater or equal to 90, return "A"
    -   Greater or equal to 80, return "B"
    -   Greater or equal to 70, return "C"
    -   Greater or equal to 60, return "D"
    -   Anything less, than 60 return "E" but greater or equal to 0
    -   If argument is negative or greater than 100, return "X"

## `pass_or_fail`

This function determines if a student passed or failed a class, based on their final letter grade.
Letter grades equal to "A", "B", "C", or "D" are passing grades (`"Pass"`).

## Calculate percentage -- `point_grade` function

This function calculates a percentage grade based on a `score` and `total_points`. It calculates the percentage grade by dividing score by total_points, and multiplies result by 100. It returns the calculated percentage as a float rounded at two decimals

## Calculate final grade -- `get_grade_results` function

This function takes two `score` and `total_points`, and it calls the previous functions you've written -- DO NOT recalculate percentage of grade, letter grade, etc. in this function. You are required to call the other functions.  It returns a message similar to: `Your grade is 92.34 (A - Pass)` or `Your grade is 35.78 (E - Fail)`

## Test Cases

```{python}
#| eval: false
#| echo: true
def main():
  # test letter_grade function
  assert letter_grade(90) == "A"
  assert letter_grade(80) == "B"
  assert letter_grade(70) == "C"
  assert letter_grade(60) == "D"
  assert letter_grade(59) == "E"
  assert letter_grade(-59) == "X"
  assert letter_grade(110) == "X"
  
  # test pass_or_fail function
  assert pass_or_fail("B") == "Pass"
  assert pass_or_fail("E") == "Fail"
  assert pass_or_fail("ABCD") == "Error"
  
  # test point_grade function
  assert point_grade(0, 100) == 0.0
  assert point_grade(100, 100) == 100.0
  assert point_grade(45, 80) == 56.25
  assert point_grade(37, 40) == 92.5
  
  # test get_grade_results function
  assert get_grade_results(0, 100) == "Your grade is 0.0 (E - Fail)"
  assert get_grade_results(45, 80) == "Your grade is 56.25 (E - Fail)"
  assert get_grade_results(37, 40) == "Your grade is 92.5 (A - Pass)"
  
main()
```