I have an assignment for school and one of the tasks is to display the grades that the students will be receiving. The grades are:

- A: 90% +
- B: 80% - 89%
- C: 70% - 79%
- D: 60% - 69%
- E: 50% - 59%

Here is some of the file, it's a comma-separated CSV file:

```
StudentName Score
Harrison 64
Jake 68
Jake 61
Hayley 86
```

I would like to know/get some guidance so I have a better understanding how to create the grade calculator. I have spent ages trying to work it out but have had no hope. My code:

```
def determine_grade(scores):if scores >= 90 and <= 100:return 'A'elif scores >= 80 and <= 89:return 'B'elif scores >= 70 and <= 79:return 'C'elif scores >= 60 and <= 69:return 'D'elif scores >= 50 and <= 59:return 'E'else:return 'F'
```