Method push

Lib/contextlib.py:495–513

Registers a callback with the standard __exit__ method signature. Can suppress exceptions the same way __exit__ method can. Also accepts any object with an __exit__ method (registering a call to the method instead of the object itself).

(self, exit)

        return new_stack

    def push(self, exit):
        """Registers a callback with the standard __exit__ method signature.

        Can suppress exceptions the same way __exit__ method can.
        Also accepts any object with an __exit__ method (registering a call
        to the method instead of the object itself).
        """
        # We use an unbound method rather than a bound method to follow
        # the standard lookup behaviour for special methods.
        _cb_type = type(exit)

        try:
            exit_method = _cb_type.__exit__
        except AttributeError:
            # Not a context manager, so assume it's a callable.
            self._push_exit_callback(exit)
        else:
            self._push_cm_exit(exit, exit_method)
        return exit  # Allow use as a decorator.

    def enter_context(self, cm):
        """Enters the supplied context manager.