How to change a two-dimensional array print into normal?

[acurate]

Homework Statement

I made a two-dimensional array program, but now I need some help to alter the program in the print zone.

The Attempt at a Solution

    import sys
    students = []
    grades = []
   
    while True:
        student = input ("Enter a name: ").replace(" ","")
        if  student.isalpha() == True and student != "0":
            while True:
                grade = input("Enter a grade: ").replace(" ","")
                if grade == "0" or grade == 0:
                    print ("\n")
                    print ("A zero is entered.")
                    sys.exit(0)
                if grade.isdigit()== True: 
                    grade = int(grade)
                    if grade >= 1 and grade <= 10:
                        if student in students:
                            index = students.index(student)
                            grades[index].append(grade)
                            break
                        else:
                            students.append(student)
                            grades.append([grade])
                            break
                    else:
                        print("Invalid grade.")
        elif student == "0": 
            print("A zero is entered.")
            break
        else:
            print ("Invalid name.")
    for i in range(0,len(students)): 
        print("NAME: ", students[i])
        print("GRADE: ", grades[i])
        print("AVERAGE: ", round(sum(grades[i])/len(grades[i]),1), "\n")

It prints out like this:

    NAME:  Jack
    GRADE:  [8, 7, 9]
    AVERAGE:  8.0

How do I turn the

GRADE:  [8, 7, 9]

so that the numbers would go

GRADE: 8, 7, 9

?[/B]

 

[Mark44]

The short answer is, you can't print the grades without the brackets. The reason for this is how your program is working. For a given student, your grades list contains only one element -- a list of the grades that you enter using this line:

grade = input("Enter a grade: ").replace(" ","")

When you append grade to your grades list, this list looks like so in memory:
grades[0] -- [8, 7, 9]
grades[1] -- empty
grades[2] -- empty
etc.
The fix for this is that after you input each grade (not all of them at once), you append that grade to your list.

Here's some code that I wrote that fixes the problem. It works correctly for a single student, but it doesn't work correctly if you enter more than one student, since grades is only one list -- IOW, there are not separate grades lists for each student. You might consider making grades a list of lists, where the list at index 1 contains the grades for student 1, and the list at index 2 contains the grades for student 2, and so on.

import sys
students = []
grades = []
sum_grades = 0

while True:
    student = input ("Enter a name: ").replace(" ","")
    if  student.isalpha() == True and student != "0":
        students.append(student)
        while True:
            grade = input("Enter a grade: ")
            if grade == "0" or grade == 0:
                print ("\n")
                print ("A zero is entered.")
                break
            if grade.isdigit()== True:
                grade = int(grade)
                if grade >= 1 and grade <= 10:
                    grades.append(grade)
                else:
                    print("Invalid grade.")

   else:
       break

students_len = len(students)
grades_len = len(grades)
for i in range(students_len):
    print("NAME: ", students[i])
    print('GRADE:', end=' ')
    for j in range(grades_len):
        grade = grades[j]
        sum_grades = sum_grades + grade
        print(grade, end=' ')
        print("\n")
        print("AVERAGE: ", round(sum_grades/len(grades)), "\n")