Sep 13, 2021 · Sep 12, 2021
diff --git a/doc/api/next_api_changes/deprecations/21056-AL.rst b/doc/api/next_api_changes/deprecations/21056-AL.rst
 Calling ``MarkerStyle()`` with no arguments
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 ... is deprecated; use ``MarkerStyle("")`` to construct an empty marker style.
diff --git a/lib/matplotlib/markers.py b/lib/matplotlib/markers.py
                                      rotated by ``angle``.
 ============================== ====== =========================================

 ``None``is the default whichmeans 'nothing', however this table is
 referred to fromotherdocs for the valid inputs frommarker inputs and in
 those cases ``None`` still means 'default'.
 ``None``alsomeans 'nothing' when directly constructing a `.MarkerStyle`, but
 note that there areothercontexts where ``marker=None`` instead means "the
 default marker" (e.g. :rc:`scatter.marker` for `.Axes.scatter`).

 Note that special symbols can be defined via the
 :doc:`STIX math font </tutorials/text/mathtext>`,
 """

 from collections.abc import Sized
 import inspect

 import numpy as np

    # TODO: Is this ever used as a non-constant?
    _point_size_reduction = 0.5

    def __init__(self, marker=None, fillstyle=None):
    _unset = object()  # For deprecation of MarkerStyle(<noargs>).

    def __init__(self, marker=_unset, fillstyle=None):
        """
        Parameters
        ----------
        marker : str, array-like, Path, MarkerStyle, or None, default: None
        marker : str, array-like, Path, MarkerStyle, or None
            - Another instance of *MarkerStyle* copies the details of that
              ``marker``.
            - *None* means no marker.
            - *None* means no marker.  This is the deprecated default.
            - For other possible marker values see the module docstring
              `matplotlib.markers`.

        """
        self._marker_function = None
        self._set_fillstyle(fillstyle)
        # Remove _unset and signature rewriting after deprecation elapses.
        if marker is self._unset:
            marker = ""
            _api.warn_deprecated(
                "3.6", message="Calling MarkerStyle() with no parameters is "
                "deprecated since %(since)s; support will be removed "
                "%(removal)s.  Use MarkerStyle('') to construct an empty "
                "MarkerStyle.")
        self._set_marker(marker)

    __init__.__signature__ = inspect.signature(  # Only for deprecation period.
        lambda self, marker, fillstyle=None: None)

    def _recache(self):
        if self._marker_function is None:
            return
diff --git a/lib/matplotlib/tests/test_marker.py b/lib/matplotlib/tests/test_marker.py
 import numpy as np
 import matplotlib.pyplot as plt
 from matplotlib import markers
 from matplotlib._api.deprecation import MatplotlibDeprecationWarning
 from matplotlib.path import Path
 from matplotlib.testing.decorators import check_figures_equal

    (5, 0, 10),  # a pentagon, rotated by 10 degrees
    (7, 1, 10),  # a 7-pointed star, rotated by 10 degrees
    (5, 2, 10),  # asterisk, rotated by 10 degrees
    markers.MarkerStyle(),
    markers.MarkerStyle('o'),
 ])
 def test_markers_valid(marker):
    # Checking this doesn't fail.
    markers.MarkerStyle(marker)


 def test_deprecated_marker_noargs():
    with pytest.warns(MatplotlibDeprecationWarning):
        ms = markers.MarkerStyle()
    markers.MarkerStyle(ms)  # No warning on copy.


 @pytest.mark.parametrize('marker', [
    'square',  # arbitrary string
    np.array([[-0.5, 0, 1, 2, 3]]),  # 1D array
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		Calling ``MarkerStyle()`` with no arguments
		~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
		... is deprecated; use ``MarkerStyle("")`` to construct an empty marker style.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -63,9 +63,9 @@
		rotated by ``angle``.
		============================== ====== =========================================

		``None``is the default whichmeans 'nothing', however this table is
		referred to fromotherdocs for the valid inputs frommarker inputs and in
		those cases ``None`` still means 'default'.
		``None``alsomeans 'nothing' when directly constructing a `.MarkerStyle`, but
		note that there areothercontexts where ``marker=None`` instead means "the
		default marker" (e.g. :rc:`scatter.marker` for `.Axes.scatter`).

		Note that special symbols can be defined via the
		:doc:`STIX math font </tutorials/text/mathtext>`,
Expand DownExpand Up		@@ -127,6 +127,7 @@
		"""

		from collections.abc import Sized
		import inspect

		import numpy as np

Expand DownExpand Up		@@ -216,14 +217,16 @@ class MarkerStyle:
		# TODO: Is this ever used as a non-constant?
		_point_size_reduction = 0.5

		def __init__(self, marker=None, fillstyle=None):
		_unset = object() # For deprecation of MarkerStyle(<noargs>).

		def __init__(self, marker=_unset, fillstyle=None):
		"""
		Parameters
		----------
		marker : str, array-like, Path, MarkerStyle, or None, default: None
		marker : str, array-like, Path, MarkerStyle, or None
		- Another instance of MarkerStyle copies the details of that
		``marker``.
		- None means no marker.
		- None means no marker. This is the deprecated default.
		- For other possible marker values see the module docstring
		`matplotlib.markers`.

Expand All		@@ -232,8 +235,19 @@ def __init__(self, marker=None, fillstyle=None):
		"""
		self._marker_function = None
		self._set_fillstyle(fillstyle)
		# Remove _unset and signature rewriting after deprecation elapses.
		if marker is self._unset:
		marker = ""
		_api.warn_deprecated(
		"3.6", message="Calling MarkerStyle() with no parameters is "
		"deprecated since %(since)s; support will be removed "
		"%(removal)s. Use MarkerStyle('') to construct an empty "
		"MarkerStyle.")
		self._set_marker(marker)

		__init__.__signature__ = inspect.signature( # Only for deprecation period.
		lambda self, marker, fillstyle=None: None)

		def _recache(self):
		if self._marker_function is None:
		return
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -1,6 +1,7 @@
		import numpy as np
		import matplotlib.pyplot as plt
		from matplotlib import markers
		from matplotlib._api.deprecation import MatplotlibDeprecationWarning
		from matplotlib.path import Path
		from matplotlib.testing.decorators import check_figures_equal

Expand DownExpand Up		@@ -32,14 +33,19 @@ def test_marker_fillstyle():
		(5, 0, 10), # a pentagon, rotated by 10 degrees
		(7, 1, 10), # a 7-pointed star, rotated by 10 degrees
		(5, 2, 10), # asterisk, rotated by 10 degrees
		markers.MarkerStyle(),
		markers.MarkerStyle('o'),
		])
		def test_markers_valid(marker):
		# Checking this doesn't fail.
		markers.MarkerStyle(marker)


		def test_deprecated_marker_noargs():
		with pytest.warns(MatplotlibDeprecationWarning):
		ms = markers.MarkerStyle()
		markers.MarkerStyle(ms) # No warning on copy.


		@pytest.mark.parametrize('marker', [
		'square', # arbitrary string
		np.array([[-0.5, 0, 1, 2, 3]]), # 1D array
Expand Down