This program requires a main function and a custom value-returning function.

In the main function, code these basic steps in this sequence (intermediate steps may be missing):

• start with an empty dictionary that represents a gradebook and then use a while loop to allow the input of course codes from the keyboard. End the while loop when the user presses enter without entering data.
• within the while loop:
  • for each course entered, use a list comprehension to generate five random integers in the range of 70 through 100. These random integers in a list represent the grades for the course. 
• after entering the courses, call a custom function passing to it the dictionary now populated with course information and associated grade information

In the custom function:

• first print the underlined headings for Course, Average Grade and Grades columns. See the example output for proper formatting (hint: use an 8-character width, left justified for "Course"; use 5-character width, centered, for "Avg"; and use 25-character width for "Grades")
• use a for loop and the items method to extract the course and grade data from gradebook.
• within the for loop:
  • use a built-in method to sort the list of grades
  • use another for loop to sum all grades for the course
  • calculate the average for the course using the sum of all grades and a built-in function to determine the number of grades in the list of grades
  • use an if statement to determine the course with the lowest average (hint: this may require initializing the variable used to store the lowest average to the highest possible grade value prior to the for loop). 
  • print the course and its average. Use format identifiers to allow for printing of a left-justified course with a width of 8 and for an average with a width of 4 including 1 decimal place.
  • use another for loop to print all grades in the grades list for the course. Use a format identifier to allow for printing of a right-justified grade with a width of 4 followed by a percent sign.
• calculate and print the term average using the previously calculated sum of all grades and built-in functions to determine the number items in the gradebook dictionary and grade list. Use a format identifier to allow for printing of a grade with a width of 4 including one decimal position followed by a percent sign.
• return the course with the lowest average

Back in main function:

• print a message indicating that the lowest grades are being dropped.  See the example output for proper formatting.
• use a for loop and the values method of the gradebook to extract the grades list for each course
• within the for loop
  • use a built-in function to determine the lowest grade from the grades list for a particular course
  • use a built-in function to remove the lowest grade
• print a message indicating that courses and grades are being printed after the lowest grades have been dropped.  See the example output for proper formatting.
• call the custom function again passing to it the updated dictionary now populated with course information and associated grade information with the lowest grades for each course dropped
• drop the lowest course, which is returned by the custom function, from the gradebook. Use a built-in function to drop the course.
• print a message indicating that courses and grades are being printed after the lowest course has been dropped.  See the example output for proper formatting.
• call the custom function again passing to it the updated dictionary now populated with course information and associated grade information with the lowest course dropped
• For your testing purposes, enter at least five courses although any amount should be allowed to be entered