Apr 1, 2025
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
        window title is set to this value.  If num is a ``SubFigure``, its
        parent ``Figure`` is activated.

        If *num* is a Figure instance that is already tracked in pyplot, it is
        activated. If *num* is a Figure instance that is not tracked in pyplot,
        it is added to the the tracked figures and activated.

    figsize : (float, float), default: :rc:`figure.figsize`
        Width, height in inches.

    in the matplotlibrc file.
    """
    allnums = get_fignums()
    next_num = max(allnums) + 1 if allnums else 1

    if isinstance(num, FigureBase):
        # type narrowed to `Figure | SubFigure` by combination of input and isinstance
        has_figure_property_parameters = (
            any(param is not None for param in [figsize, dpi, facecolor, edgecolor])
            or not frameon or kwargs
        )

        root_fig = num.get_figure(root=True)
        if root_fig.canvas.manager is None:
            raise ValueError("The passed figure is not managed by pyplot")
        elif (any(param is not None for param in [figsize, dpi, facecolor, edgecolor])
              or not frameon or kwargs) and root_fig.canvas.manager.num in allnums:
            if has_figure_property_parameters:
                raise ValueError(
                    "You cannot pass figure properties when calling figure() with "
                    "an existing Figure instance")
            backend = _get_backend_mod()
            manager_ = backend.new_figure_manager_given_figure(next_num, root_fig)
            _pylab_helpers.Gcf._set_new_active_manager(manager_)
            return manager_.canvas.figure
        elif has_figure_property_parameters and root_fig.canvas.manager.num in allnums:
            _api.warn_external(
                "Ignoring specified arguments in this call because figure "
                f"with num: {root_fig.canvas.manager.num} already exists")
        _pylab_helpers.Gcf.set_active(root_fig.canvas.manager)
        return root_fig

    next_num = max(allnums) + 1 if allnums else 1
    fig_label = ''
    if num is None:
        num = next_num
diff --git a/lib/matplotlib/tests/test_figure.py b/lib/matplotlib/tests/test_figure.py
    assert plt.get_figlabels() == ['', 'today']
    plt.figure(fig_today)
    assert plt.gcf() == fig_today
    with pytest.raises(ValueError):
        plt.figure(Figure())


 def test_figure_label_replaced():
diff --git a/lib/matplotlib/tests/test_pyplot.py b/lib/matplotlib/tests/test_pyplot.py
    assert fig is fig3


 def test_register_existing_figure_with_pyplot():
    from matplotlib.figure import Figure
    # start with a standalone figure
    fig = Figure()
    assert fig.canvas.manager is None
    with pytest.raises(AttributeError):
        # Heads-up: This will change to returning None in the future
        # See docstring for the Figure.number property
        fig.number
    # register the Figure with pyplot
    plt.figure(fig)
    assert fig.number == 1
    # the figure can now be used in pyplot
    plt.suptitle("my title")
    assert fig.get_suptitle() == "my title"
    # it also has a manager that is properly wired up in the pyplot state
    assert plt._pylab_helpers.Gcf.get_fig_manager(fig.number) is fig.canvas.manager
    # and we can regularly switch the pyplot state
    fig2 = plt.figure()
    assert fig2.number == 2
    assert plt.figure(1) is fig
    assert plt.gcf() is fig


 def test_close_all_warning():
    fig1 = plt.figure()
Original file line number	Diff line number	Diff line change
Expand Up		@@ -908,6 +908,10 @@
		window title is set to this value. If num is a ``SubFigure``, its
		parent ``Figure`` is activated.

		If num is a Figure instance that is already tracked in pyplot, it is
		activated. If num is a Figure instance that is not tracked in pyplot,
		it is added to the the tracked figures and activated.

		figsize : (float, float), default: :rc:`figure.figsize`
		Width, height in inches.

Expand DownExpand Up		@@ -990,21 +994,32 @@
		in the matplotlibrc file.
		"""
		allnums = get_fignums()
		next_num = max(allnums) + 1 if allnums else 1

		if isinstance(num, FigureBase):
		# type narrowed to `Figure \| SubFigure` by combination of input and isinstance
		has_figure_property_parameters = (
		any(param is not None for param in [figsize, dpi, facecolor, edgecolor])
		or not frameon or kwargs
		)

		root_fig = num.get_figure(root=True)
		if root_fig.canvas.manager is None:
		raise ValueError("The passed figure is not managed by pyplot")
		elif (any(param is not None for param in [figsize, dpi, facecolor, edgecolor])
		or not frameon or kwargs) and root_fig.canvas.manager.num in allnums:
		if has_figure_property_parameters:
		raise ValueError(
Check warning on line 1009 in lib/matplotlib/pyplot.py View check run for this annotation Codecov/ codecov/patch lib/matplotlib/pyplot.py#L1009 `Added line #L1009 was not covered by tests`
		"You cannot pass figure properties when calling figure() with "
		"an existing Figure instance")
		backend = _get_backend_mod()
		manager_ = backend.new_figure_manager_given_figure(next_num, root_fig)
		_pylab_helpers.Gcf._set_new_active_manager(manager_)
		return manager_.canvas.figure
		elif has_figure_property_parameters and root_fig.canvas.manager.num in allnums:
		_api.warn_external(
		"Ignoring specified arguments in this call because figure "
		f"with num: {root_fig.canvas.manager.num} already exists")
		_pylab_helpers.Gcf.set_active(root_fig.canvas.manager)
		return root_fig

		next_num = max(allnums) + 1 if allnums else 1
		fig_label = ''
		if num is None:
		num = next_num
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -147,8 +147,6 @@ def test_figure_label():
		assert plt.get_figlabels() == ['', 'today']
		plt.figure(fig_today)
		assert plt.gcf() == fig_today
		with pytest.raises(ValueError):
		plt.figure(Figure())


		def test_figure_label_replaced():
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -470,6 +470,30 @@ def test_multiple_same_figure_calls():
		assert fig is fig3


		def test_register_existing_figure_with_pyplot():
		from matplotlib.figure import Figure
		# start with a standalone figure
		fig = Figure()
		assert fig.canvas.manager is None
		with pytest.raises(AttributeError):
		# Heads-up: This will change to returning None in the future
		# See docstring for the Figure.number property
		fig.number
		# register the Figure with pyplot
		plt.figure(fig)
		assert fig.number == 1
		# the figure can now be used in pyplot
		plt.suptitle("my title")
		assert fig.get_suptitle() == "my title"
		# it also has a manager that is properly wired up in the pyplot state
		assert plt._pylab_helpers.Gcf.get_fig_manager(fig.number) is fig.canvas.manager
		# and we can regularly switch the pyplot state
		fig2 = plt.figure()
		assert fig2.number == 2
		assert plt.figure(1) is fig
		assert plt.gcf() is fig


		def test_close_all_warning():
		fig1 = plt.figure()

Expand Down