A class can have any number of member variables. These are variables that are available to all members of a class.

hippo = Animal("Jake", 12)
cat = Animal("Boots", 3)
print hippo.is_alive
hippo.is_alive = False
print hippo.is_alive
print cat.is_alive

1. In the example above, we create two instances of an Animal.
2. Then we print out True, the default value stored in hippo’s is_alive member variable.
3. Next, we set that to False and print it out to make sure.
4. Finally, we print out True, the value stored in cat’s is_alive member variable. We only changed the variable in hippo, not in cat.

Let’s add another member variable to Animal.