[Tutor] OO Python: How to change attributes of just one object in a list

[Andrei Kulakov]

On Mon, May 20, 2002 at 02:34:13AM -0400, Geoffrey Bays wrote:
> I am trying to write an OO program in Python to keep track of students in 
> classes of mine. Unfortunately, the changeGrade() method in class Course 
> changes all of the students' grades on the same test to the same grade.
> I have determined that the for and if clauses work correctly, and have 
> tried defining __eq__() and __del__ in the Student class, writing a 
> changeGrade method in class Student, etc, but none of this does any good. I 
> just want to push student objects onto the studentList and change their 
> grades individually.
> Any help would be much appreciated.
> 
> class Student:
>    def __init__(self, name):
>    self.name = name
>    self.record = {}
> 
> def display(self):
>    print self.name, '\n'
>    for item in self.record.keys(): print item, '\t', self.record[item],
>    print '\n'
> 
> class Course:
>    def __init__(self,name):
>    self.name = name
>    self.tests = {}
>    self.design()
>    self.studentList = []
> 
> def design(self):
>    s = raw_input('Enter graded items for the course separated by commas:\
>    test = s.split(",")
>    for X in test:
>       self.tests[X] = -1
> 
> def display(self):
>    print c.name," "
>    for test in c.tests.keys(): print test,": ",c.tests[test],
>    print '\n'
> 
> def addStudent(self,name):
>    s = Student(name)
>    s.record = self.tests
>    self.studentList.append(s)
> 
> def displayCourse(self):
>    for i in range(len(self.studentList)):
>      self.studentList[i].display()
> 
> def changeGrade(self,studName,test,score):
> boolean = 0
> for i in range(len(self.studentList)):
>     if(self.studentList[i].name == studName ):
>     self.studentList[i].record[test] = score       //This is the line that 
> changes all the students grades, not just the one
>     boolean = 1
> if (boolean == 0):
> print "No student of that name found."
>
> 
> 
>
This does not show up correctly formatted here.. could you please
repost? Also add some test code.

Wouldn't it be better though to store students in a dictionarary
with names as keys, instead of a list?

Then you can changeGrade as:
    students[name].record[test] = score

Actually, it *should* be in Student class:
    self.record[test] = score

> 
> 
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