I am having a very hard time trying to write this program. Any suggestions to make it easier to understand?

Create code and a flowchart

Exercise 3: Write a program to prompt for a score between 0.0 and 1.0. If the score is out of range, print an error message. If the score is between 0.0 and 1.0, print a grade using the following table:

 Score Grade >= 0.9 A >= 0.8 B >= 0.7 C >= 0.6 D < 0.6 F

Enter score: 0.95 A

Enter score: perfect Bad score

Enter score: 10.0 Bad score

Enter score: 0.75 C

Enter score: 0.5 F

Beginning Python