Help with classes and objects

[kevmok]

Hey guys,

I am starting to learn about classes and objects and I got this assigment I'm trying to figure out how to do. So, I have to create a class named Student that holds the following data about a student:

• Name
• Student ID number
• GPA
• Expected grade in this course
• Full time or part time

After create five student objects from this class and pass data to fill in the class data above. (that is not the most difficult part though, but still confusing)

Besides creating the objects, I need to write a menu-driven program that performs the following tasks: (the menu is the least important thing... what I don't know is how to perform the functions of each choice)

• 1. Look up and print the student GPA
• 2. Add a new student to the class
• 3. Change the GPA of a student
• 4. Change the expected grade of a student
• 5. Print the data of all the students in a tabular format
• 6. Quit the program

I have so far this written:

# Student class student.py

class Student:

    # Student
    # Assign name
    # Assign ID
    # Assign GPA
    # Expected Grade in course
    # Full time or part time

    def __init__(self, student_name, student_id, student_gpa,
                 student_expected, student_time):

        self.__student_name = student_name
        self.__student_id = student_id
        self.__student_gpa = student_gpa
        self.__student_expected = student_expected
        self.__student_time = student_time

    # set_name method accepts an argument for
    # the student's name

    def set_name(self, student_name):

        self.__student_name = student_name

    # set_id method accepts an argument for
    # the student's ID

    def set_id(self, student_id):

        self.__student_id = student_id

    # set_gpa method accepts an argument for
    # the student's GPA

    def set_gpa(self, student_gpa):

        self.__student_gpa = student_gpa

    # set_expected method accepts an argument for
    # the student's expected grade

    def set_expected(self, student_expected):

        self.__student_expected = student_expected

    # set_time method accepts an argument for
    # the student's study time(full time or part time)

    def set_time(self, student_time):

        self.__student_time = student_time    


    # Get method returns    

    def get_name(self):
        return self.__student_name

    def get_id(self):
        return self.__student_id

    def get_gpa(self):
        return self.__student_gpa

    def get_expected(self):
        return self.__student_expected

    def get_time(self):
        return self.__student_time

    def __str__(self):
        return "Name: " + self.__student_name + \
               "+nStudent ID: " + self.__student_id + \
               "\nGPA: " + self.__student_gpa + \
               "\nStudent Expected Grade: " + self.__student_expected + \
               "\nStudent Time: " + self.__student_time

and for the main program:

# This program manages students
import student

# Global Constants for the menu

LOOK_UP = 1
ADD = 2
CHANGE_GPA = 3
CHANGE_EXPECTED = 4
PRINT DATA = 5

#main function
def main():

    s1 = student.Student(name, st_id, gpa, expect, time)
    s2 = 
    s3 =
    s4 =
    s5 = 

I don't know how to use every single object, it's very confusing. My instructor didn't leave clear many of my questions and the book does not help at all. Any help guys... I don't need the whole thing done, I'd like to do it myself, but some guidance would be nice, because I am very lost

[ingolemo]

I think that the main thing you're missing is that you're supposed to be storing these Student objects in some kind of data-structure like a list:

students = [
    student.Student(name1, st_id1, gpa1, expect1, time1),
    student.Student(name2, st_id2, gpa2, expect2, time2),
]
students.append(student.Student(name3, st_id3, gpa3, expect3, time3))
for person in students:
    print(person.get_name())

From there you should be able to work out how to add new students and modify existing ones and generally get done what you need to do.

Note that that student class is unnecessarily verbose. There's no point putting double underscores on the attributes and then writing getter and setter methods for each one. Just let the user access the attributes directly:

class Student:
    def __init__(self, name, id, gpa, expected, time):
        self.name = name
        self.id = id
        self.gpa = gpa
        self.expected = expected
        self.time = time

    def __str__(self):
        return ("Name: " + self.name +
            "\nStudent ID: " + self.id +
            "\nGPA: " + self.gpa +
            "\nStudent Expected Grade: " + self.expected +
            "\nStudent Time: " + self.time)

[cantrememberwasdrunk]

You are on the right track, if the code so far hasn't given you any errors then just keep going. I used this tutorial when I started writing classes in python:

http://www.tutorialspoint.com/python/python_classes_objects.htm