What is Class or Static Variables in Python ?

class CSStudent:
stream = 'cse' # Class Variable
def __init__(self,name,roll):
self.name = name # Instance Variable
self.roll = roll # Instance Variable

# Objects of CSStudent class
a = CSStudent('Geek', 1)
b = CSStudent('Nerd', 2)

print(a.stream) # prints "cse"
print(b.stream) # prints "cse"
print(a.name) # prints "Geek"
print(b.name) # prints "Nerd"
print(a.roll) # prints "1"
print(b.roll) # prints "2"

# Class variables can be accessed using class
# name also
print(CSStudent.stream) # prints "cse"

# Now if we change the stream for just a it won't be changed for b
a.stream = 'ece'
print(a.stream) # prints 'ece'
print(b.stream) # prints 'cse'

# To change the stream for all instances of the class we can change it
# directly from the class
CSStudent.stream = 'mech'

print(a.stream) # prints 'ece'
print(b.stream) # prints 'mech'


Output:


cse
cse
Geek
Nerd
1
2
cse
ece
cse
ece
mech