A metaclass is a class which has classes as its instances. Like an "ordinary" class defines the behavior of the instances of the class, a metaclass also defines the behavior of its classes and their instances.
Metaclasses are supported by Python. Some programmers consider metaclasses in Python as "solutions waiting or looking for a problem".
There are numerous applications of metaclasses. Few of them are −
logging and profiling;
registering classes at creation time;
automatically adding new methods;
automatic property creation;