__metaclass__ in Python 3
Python 3 changed how you specify a metaclass, __metaclass__
is no longer checked.
Use metaclass=...
in the class signature:
class Table(object, metaclass=MetaTable):
Demo:
>>> class MetaTable(type):
... def __getattr__(cls, key):
... temp = key.split("__")
... name = temp[0]
... alias = None
... if len(temp) > 1:
... alias = temp[1]
... return cls(name, alias)
...
>>> class Table(object, metaclass=MetaTable):
... def __init__(self, name, alias=None):
... self._name = name
... self._alias = alias
...
>>> d = Table
>>> d.student__s
<__main__.Table object at 0x10d7b56a0>
If you need to provide support for both Python 2 and 3 in your codebase, you can use the six.with_metaclass()
baseclass generator or the @six.add_metaclass()
class decorator to specify the metaclass.