When we declare a variable inside a class but outside any method, it is called as class or static variable in python. Class or static variable can be referred through a class but not directly through an instance.
Class or static variable are quite distinct from and does not conflict with any other member variable with the same name. Below is a program to demonstrate the use of class or static variable −
class Fruits(object): count = 0 def __init__(self, name, count): self.name = name self.count = count Fruits.count = Fruits.count + count def main(): apples = Fruits("apples", 3); pears = Fruits("pears", 4); print (apples.count) print (pears.count) print (Fruits.count) print (apples.__class__.count) # This is Fruit.count print (type(pears).count) # So is this if __name__ == '__main__': main()
3 4 7 7 7
Another example to demonstrate the use of variable defined on the class level −
class example: staticVariable = 9 # Access through class print (example.staticVariable) # Gives 9 #Access through an instance instance = example() print(instance.staticVariable) #Again gives 9 #Change within an instance instance.staticVariable = 12 print(instance.staticVariable) # Gives 12 print(example.staticVariable) #Gives 9
9 9 12 9