Embedding Example Bug?

从 examples/embedding/internal_ipkernel.py 开始，重点查看 new_qt_console 和 cleanup_consoles。跟踪此示例中控制台的创建和跟踪方式，然后验证 cleanup_consoles 能够作用于通过该示例打开的控制台，并且 no-op 行为已得到解决。

https://github.com/ipython/ipykernel/blob/master/examples/embedding/internal_ipkernel.py

class InternalIPKernel(object):

    def init_ipkernel(self, backend):
        # Start IPython kernel with GUI event loop and mpl support
        self.ipkernel = mpl_kernel(backend)
        # To create and track active qt consoles
        self.consoles = []
        
        # This application will also act on the shell user namespace
        self.namespace = self.ipkernel.shell.user_ns

        # Example: a variable that will be seen by the user in the shell, and
        # that the GUI modifies (the 'Counter++' button increments it):
        self.namespace['app_counter'] = 0
        #self.namespace['ipkernel'] = self.ipkernel  # dbg

    def print_namespace(self, evt=None):
        print("\n***Variables in User namespace***")
        for k, v in self.namespace.items():
            if not k.startswith('_'):
                print('%s -> %r' % (k, v))
        sys.stdout.flush()

    def new_qt_console(self, evt=None):
        """start a new qtconsole connected to our kernel"""
        return connect_qtconsole(self.ipkernel.abs_connection_file, profile=self.ipkernel.profile)

    def count(self, evt=None):
        self.namespace['app_counter'] += 1

    def cleanup_consoles(self, evt=None):
        for c in self.consoles:
            c.kill()

self.consoles is not appended anywhere in the class, so the cleanup will just be a no-op.