Python class initialization for newbie

Question

First I make a python file clss.py

class A:
 def __init__(self, a):
 A.a = a
class B(A):
 def __init__(self, b, c):
 B.b = b
 if c:
 B.c = c
 else:
 B.c = '0'
def get_list(csv_filename):
 test_list = []
 with open(csv_filename) as csv_file:
 reader = csv.reader(csv_file, delimiter=';')
 next(reader)
 try:
 for row in reader:
 test_list.append(B(row[0], row[1], row[2]))
 except:
 pass
 return test_list

Then I read a csv file from prog.py where some 'None' values exists and a lot of normal values:

from clss.py import *
test = get_list('my_file.csv')
for i in test:
 print(i.c)

And it gives me all '0'

• juanpa.arrivillaga: Why are you using B.c? There is only one of those.
• juanpa.arrivillaga: And actually, I'm surprised you are getting any output. You should always fail here: test_list.append(B(row[0], row[1], row[2])) because the B constructor only takes two arguments, but you are passing 3. You really should do something like try: ... except: pass.
• jjramsey: I strongly suspect that when you write A.a = a, you really mean self.a = a. Same goes for instances of B.b and B.c.
• H S: Yep guys you are right. I've missed 'a' while copying the code here. In my initial code 'a' is present in class 'B'

Answer 1

When you write B.c = '0', you set the variable at the class level, so all your objects will have the same value.

Replace all B. with self. in your class B. The same for class A with A..