Create and call variables in python

Question

I am new in python and have a simple question… In my project there is an "student" class, and there are some student object (for example 100):

class students:
    def __init__(self, name):
        self.name = name

Some of these students are special (for example five), now I want to define three variables z0, z1, z2 for each of these five special students:

for c in self.candidate_student:
   z0 
   z1 
   z2

After this part, I want to call each candidate student variable by name, like this:

student.name.z0
student.name.z1
student.name.z2

Can anyone explain how I can achieve this?

Answer 1

If you meant to define z0,z1 and z2 values for each of the 'special' students, you can set them as attributes of the object instances. Note you can add a new attribute to an object at any time, it doesn't have to be in the __init__() method. For example, if you are creating a new 'special student' object:

s = student("John Doe")
s.z0 = 7
s.z1 = 8
s.z2 = 9

Now, s just got three new attributes (besides name, which you set in __init__), you can address them like variables anywhere after they have been set. E.g., after the above:

print (s.name) # will print "John Doe"
print (s.z2) # will print 9

Note if you have code that works with both 'special' and 'non-special' objects, you should expect that the special attributes aren't always there (so if you try to use student.z0 on an object that didn't have that set beforehand, you will get an exception).

Answer 2

Since you want to add properties to your special students this code might help:

class students:
    def __init__(self, name, z=None):
        self.name = name
        self.z = z or []

You can initialize your special student like this:

ana = students('Ana', ['Apple', 'Ball', 'Pen'])

And call the properties like this:

ana.z[0]
ana.z[1]