IPython-core2.py

@magics_class
class StatefulMagics(Magics):
    "Magics that hold additional state"

    def __init__(self, shell, data):
        # You must call the parent constructor
        super(StatefulMagics, self).__init__(shell)
        self.data = data

    # etc...

def load_ipython_extension(ipython):
    """
    Any module file that define a function named `load_ipython_extension`
    can be loaded via `%load_ext module.path` or be configured to be
    autoloaded by IPython at startup time.
    """
    # This class must then be registered with a manually created instance,
    # since its constructor has different arguments from the default:
    magics = StatefulMagics(ipython, some_data)
    ipython.register_magics(magics)