Work for a score reports company and find out how students done on tests
String of comma seperated values with the test results from the schools
Build a programme that takes the string and builds a report from it.
Input | Ouput "Green" | "Green: 1" "Green, Green, Red, Amber, Red" | "Green: 2\nAmber: 1\nRed: 2"
Edge cases: "" "No results given" wrong input (not a string) : Error "Input must be a comma-separated string" incorrect spelling: "Green,Dave,Whimsy,Red" "Green: 1\nRed: 1\nUncounted: 2"
Use more descriptive name rather than input, test results or grades
makes it easier for someone to understand what the code actually does