matplotlib · oscargus · Mar 31, 2025
diff --git a/lib/matplotlib/_api/__init__.pyi b/lib/matplotlib/_api/__init__.pyi
@@ -1,6 +1,5 @@
 from collections.abc import Callable, Generator, Iterable, Mapping, Sequence
-from typing import Any, TypeVar, overload
-from typing_extensions import Self  # < Py 3.11
+from typing import Any, Self, TypeVar, overload
 
 from numpy.typing import NDArray
 

diff --git a/lib/matplotlib/_api/deprecation.pyi b/lib/matplotlib/_api/deprecation.pyi
@@ -1,9 +1,6 @@
 from collections.abc import Callable
 import contextlib
-from typing import Any, Literal, ParamSpec, TypedDict, TypeVar, overload
-from typing_extensions import (
-    Unpack,  # < Py 3.11
-)
+from typing import Any, Literal, ParamSpec, TypedDict, TypeVar, Unpack, overload
 
 _P = ParamSpec("_P")
 _R = TypeVar("_R")

diff --git a/lib/matplotlib/_mathtext.py b/lib/matplotlib/_mathtext.py
@@ -1966,9 +1966,9 @@ class _MathStyle(enum.Enum):
       """.split())
     _delims = _left_delims | _right_delims | _ambi_delims
 
-    _small_greek = set([unicodedata.name(chr(i)).split()[-1].lower() for i in
+    _small_greek = {unicodedata.name(chr(i)).split()[-1].lower() for i in
                        range(ord('\N{GREEK SMALL LETTER ALPHA}'),
-                             ord('\N{GREEK SMALL LETTER OMEGA}') + 1)])
+                             ord('\N{GREEK SMALL LETTER OMEGA}') + 1)}
     _latin_alphabets = set(string.ascii_letters)
 
     def __init__(self) -> None:

diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -4114,7 +4114,7 @@ def format_coord(self, x, y):
         for ax in sorted(twins, key=attrgetter("zorder")):
             data_x, data_y = ax.transData.inverted().transform(screen_xy)
             xy_strs.append(
-                "({}, {})".format(ax.format_xdata(data_x), ax.format_ydata(data_y)))
+                f"({ax.format_xdata(data_x)}, {ax.format_ydata(data_y)})")
         return "(x, y) = {}".format(" | ".join(xy_strs))
 
     def minorticks_on(self):

diff --git a/lib/matplotlib/axis.pyi b/lib/matplotlib/axis.pyi
@@ -1,7 +1,6 @@
 from collections.abc import Callable, Iterable, Sequence
 import datetime
-from typing import Any, Literal, overload
-from typing_extensions import Self  # < Py 3.11
+from typing import Any, Literal, Self, overload
 
 import numpy as np
 from numpy.typing import ArrayLike

diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -121,7 +121,7 @@ def _escape_and_apply_props(s, prop):
         _log.warning("Ignoring unknown font: %s", family)
 
     size = prop.get_size_in_points()
-    commands.append(r"\fontsize{%f}{%f}" % (size, size * 1.2))
+    commands.append(r"\fontsize{{{:f}}}{{{:f}}}".format(size, size * 1.2))
 
     styles = {"normal": r"", "italic": r"\itshape", "oblique": r"\slshape"}
     commands.append(styles[prop.get_style()])
@@ -416,7 +416,8 @@ def draw_markers(self, gc, marker_path, marker_trans, path, trans,
                                               clip=clip):
             x, y = point[0] * f, point[1] * f
             _writeln(self.fh, r"\begin{pgfscope}")
-            _writeln(self.fh, r"\pgfsys@transformshift{%fin}{%fin}" % (x, y))
+            _writeln(self.fh,
+                     r"\pgfsys@transformshift{{{:f}in}}{{{:f}in}}".format(x, y))
             _writeln(self.fh, r"\pgfsys@useobject{currentmarker}{}")
             _writeln(self.fh, r"\end{pgfscope}")
 
@@ -465,7 +466,7 @@ def draw_path(self, gc, path, transform, rgbFace=None):
             ymin, ymax = f * ymin, f * ymax
             repx, repy = math.ceil(xmax - xmin), math.ceil(ymax - ymin)
             _writeln(self.fh,
-                     r"\pgfsys@transformshift{%fin}{%fin}" % (xmin, ymin))
+                     r"\pgfsys@transformshift{{{:f}in}}{{{:f}in}}".format(xmin, ymin))
             for iy in range(repy):
                 for ix in range(repx):
                     _writeln(self.fh, r"\pgfsys@useobject{currentpattern}{}")
@@ -652,7 +653,7 @@ def draw_image(self, gc, x, y, im, transform=None):
         f = 1. / self.dpi  # from display coords to inch
         if transform is None:
             _writeln(self.fh,
-                     r"\pgfsys@transformshift{%fin}{%fin}" % (x * f, y * f))
+                     r"\pgfsys@transformshift{{{:f}in}}{{{:f}in}}".format(x * f, y * f))
             w, h = w * f, h * f
         else:
             tr1, tr2, tr3, tr4, tr5, tr6 = transform.frozen().to_values()
@@ -718,7 +719,7 @@ def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
         if angle != 0:
             text_args.append("rotate=%f" % angle)
 
-        _writeln(self.fh, r"\pgftext[%s]{%s}" % (",".join(text_args), s))
+        _writeln(self.fh, r"\pgftext[{}]{{{}}}".format(",".join(text_args), s))
         _writeln(self.fh, r"\end{pgfscope}")
 
     def get_text_width_height_descent(self, s, prop, ismath):

diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
@@ -151,10 +151,10 @@ def _font_to_ps_type3(font_path, chars):
         g = font.load_glyph(glyph_id, LoadFlags.NO_SCALE)
         v, c = font.get_path()
         entries.append(
-            "/%(name)s{%(bbox)s sc\n" % {
-                "name": font.get_glyph_name(glyph_id),
-                "bbox": " ".join(map(str, [g.horiAdvance, 0, *g.bbox])),
-            }
+            "/{name}{{{bbox} sc\n".format(
+                name=font.get_glyph_name(glyph_id),
+                bbox=" ".join(map(str, [g.horiAdvance, 0, *g.bbox])),
+            )
             + _path.convert_to_string(
                 # Convert back to TrueType's internal units (1/64's).
                 # (Other dimensions are already in these units.)
@@ -740,14 +740,14 @@ def draw_tex(self, gc, x, y, s, prop, angle, *, mtext=None):
                    'monospace': r'{\ttfamily %s}'}.get(
                        mpl.rcParams['font.family'][0], r'{\rmfamily %s}')
         s = fontcmd % s
-        tex = r'\color[rgb]{%s} %s' % (color, s)
+        tex = r'\color[rgb]{{{}}} {}'.format(color, s)
 
         # Stick to bottom-left alignment, so subtract descent from the text-normal
         # direction since text is normally positioned by its baseline.
         rangle = np.radians(angle + 90)
         pos = _nums_to_str(x - bl * np.cos(rangle), y - bl * np.sin(rangle))
         self.psfrag.append(
-            r'\psfrag{%s}[bl][bl][1][%f]{\fontsize{%f}{%f}%s}' % (
+            r'\psfrag{{{}}}[bl][bl][1][{:f}]{{\fontsize{{{:f}}}{{{:f}}}{}}}'.format(
                 thetext, angle, fontsize, fontsize*1.25, tex))
 
         self._pswriter.write(f"""\
@@ -981,7 +981,7 @@ def _print_ps(
         dsc_comments["CreationDate"] = (
             datetime.datetime.fromtimestamp(
                 int(source_date_epoch),
-                datetime.timezone.utc).strftime("%a %b %d %H:%M:%S %Y")
+                datetime.UTC).strftime("%a %b %d %H:%M:%S %Y")
             if source_date_epoch
             else time.ctime())
         dsc_comments = "\n".join(

diff --git a/lib/matplotlib/backends/backend_svg.py b/lib/matplotlib/backends/backend_svg.py
@@ -397,7 +397,7 @@ def _write_metadata(self, metadata):
             # See https://reproducible-builds.org/specs/source-date-epoch/
             date = os.getenv("SOURCE_DATE_EPOCH")
             if date:
-                date = datetime.datetime.fromtimestamp(int(date), datetime.timezone.utc)
+                date = datetime.datetime.fromtimestamp(int(date), datetime.UTC)
                 metadata['Date'] = date.replace(tzinfo=UTC).isoformat()
             else:
                 metadata['Date'] = datetime.datetime.today().isoformat()

diff --git a/lib/matplotlib/cbook.pyi b/lib/matplotlib/cbook.pyi
@@ -14,10 +14,10 @@ from typing import (
     Generic,
     IO,
     Literal,
-    Sequence,
     TypeVar,
     overload,
 )
+from collections.abc import Sequence
 
 _T = TypeVar("_T")
 

diff --git a/lib/matplotlib/colors.py b/lib/matplotlib/colors.py
@@ -1547,8 +1547,7 @@ def __getitem__(self, item):
         return self._colormaps[item]
 
     def __iter__(self):
-        for c in self._colormaps:
-            yield c
+        yield from self._colormaps
 
     def __len__(self):
         return len(self._colormaps)

diff --git a/lib/matplotlib/dates.py b/lib/matplotlib/dates.py
@@ -202,7 +202,7 @@
 
 
 _log = logging.getLogger(__name__)
-UTC = datetime.timezone.utc
+UTC = datetime.UTC
 
 
 def _get_tzinfo(tz=None):
@@ -1169,14 +1169,14 @@
         except (ValueError, OverflowError):
             # cap
             start = datetime.datetime(1, 1, 1, 0, 0, 0,
-                                      tzinfo=datetime.timezone.utc)
+                                      tzinfo=datetime.UTC)
 
         try:
             stop = vmax + delta
         except (ValueError, OverflowError):
             # cap
             stop = datetime.datetime(9999, 12, 31, 23, 59, 59,
-                                     tzinfo=datetime.timezone.utc)
+                                     tzinfo=datetime.UTC)
 
         self.rule.set(dtstart=start, until=stop)
 

diff --git a/lib/matplotlib/dviread.pyi b/lib/matplotlib/dviread.pyi
@@ -4,8 +4,7 @@
 from enum import Enum
 from collections.abc import Generator
 
-from typing import NamedTuple
-from typing_extensions import Self  # < Py 3.11
+from typing import NamedTuple, Self
 
 class _dvistate(Enum):
     pre = ...

diff --git a/lib/matplotlib/sankey.pyi b/lib/matplotlib/sankey.pyi
@@ -1,8 +1,7 @@
 from matplotlib.axes import Axes
 
 from collections.abc import Callable, Iterable
-from typing import Any
-from typing_extensions import Self  # < Py 3.11
+from typing import Any, Self
 
 import numpy as np
 

diff --git a/lib/matplotlib/tests/test_api.py b/lib/matplotlib/tests/test_api.py
@@ -13,7 +13,7 @@
 
 
 if typing.TYPE_CHECKING:
-    from typing_extensions import Self
+    from typing import Self
 
 T = TypeVar('T')
 

diff --git a/lib/matplotlib/tests/test_dates.py b/lib/matplotlib/tests/test_dates.py
@@ -855,7 +855,7 @@ def _create_auto_date_locator(date1, date2, tz):
         sts = [st.get_text() for st in ax.get_yticklabels()]
         return sts, ax.yaxis.get_offset_text().get_text()
 
-    d1 = datetime.datetime(1997, 1, 1).replace(tzinfo=datetime.timezone.utc)
+    d1 = datetime.datetime(1997, 1, 1).replace(tzinfo=datetime.UTC)
     results = ([datetime.timedelta(hours=40),
                 ['03:00', '07:00', '11:00', '15:00', '19:00', '23:00',
                  '03:00', '07:00', '11:00', '15:00', '19:00'],
@@ -1310,8 +1310,8 @@ def test_DateLocator():
     locator.create_dummy_axis()
     # default values
     assert locator.datalim_to_dt() == (
-        datetime.datetime(1970, 1, 1, 0, 0, tzinfo=datetime.timezone.utc),
-        datetime.datetime(1970, 1, 2, 0, 0, tzinfo=datetime.timezone.utc))
+        datetime.datetime(1970, 1, 1, 0, 0, tzinfo=datetime.UTC),
+        datetime.datetime(1970, 1, 2, 0, 0, tzinfo=datetime.UTC))
 
     # Check default is UTC
     assert locator.tz == mdates.UTC
@@ -1395,10 +1395,10 @@ def test_num2date_error(val):
 
 def test_num2date_roundoff():
     assert mdates.num2date(100000.0000578702) == datetime.datetime(
-        2243, 10, 17, 0, 0, 4, 999980, tzinfo=datetime.timezone.utc)
+        2243, 10, 17, 0, 0, 4, 999980, tzinfo=datetime.UTC)
     # Slightly larger, steps of 20 microseconds
     assert mdates.num2date(100000.0000578703) == datetime.datetime(
-        2243, 10, 17, 0, 0, 5, tzinfo=datetime.timezone.utc)
+        2243, 10, 17, 0, 0, 5, tzinfo=datetime.UTC)
 
 
 def test_DateFormatter_settz():

diff --git a/lib/matplotlib/tests/test_figure.py b/lib/matplotlib/tests/test_figure.py
@@ -1349,7 +1349,7 @@ def test_subfigure():
     fig.suptitle('Figure suptitle', fontsize='xx-large')
 
     # below tests for the draw zorder of subfigures.
-    leg = fig.legend(handles=[plt.Line2D([0], [0], label='Line{}'.format(i))
+    leg = fig.legend(handles=[plt.Line2D([0], [0], label=f'Line{i}')
                      for i in range(5)], loc='center')
     sub[0].set_zorder(leg.get_zorder() - 1)
     sub[1].set_zorder(leg.get_zorder() + 1)

diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -1086,7 +1086,7 @@
 
     def _non_decade_format(self, sign_string, base, fx, usetex):
         """Return string for non-decade locations."""
-        return r'$\mathdefault{%s%s^{%.2f}}$' % (sign_string, base, fx)
+        return r'$\mathdefault{{{}{}^{{{:.2f}}}}}$'.format(sign_string, base, fx)
 
     def __call__(self, x, pos=None):
         # docstring inherited
@@ -1118,7 +1118,7 @@
             base = '%s' % b
 
         if abs(fx) < mpl.rcParams['axes.formatter.min_exponent']:
-            return r'$\mathdefault{%s%g}$' % (sign_string, x)
+            return r'$\mathdefault{{{}{:g}}}$'.format(sign_string, x)
         elif not is_x_decade:
             usetex = mpl.rcParams['text.usetex']
             return self._non_decade_format(sign_string, base, fx, usetex)

diff --git a/lib/matplotlib/typing.py b/lib/matplotlib/typing.py
@@ -9,9 +9,9 @@
     The ``typing`` module and type stub files are considered provisional and may change
     at any time without a deprecation period.
 """
-from collections.abc import Hashable, Sequence
+from collections.abc import Callable, Hashable, Sequence
 import pathlib
-from typing import Any, Callable, Literal, TypeAlias, TypeVar, Union
+from typing import Any, Literal, TypeAlias, TypeVar, Union
 
 from . import path
 from ._enums import JoinStyle, CapStyle

diff --git a/lib/mpl_toolkits/mplot3d/axes3d.py b/lib/mpl_toolkits/mplot3d/axes3d.py
@@ -4140,7 +4140,7 @@ def __eq__(self, other):
         return (self.scalar == other.scalar) and (self.vector == other.vector).all
 
     def __repr__(self):
-        return "_Quaternion({}, {})".format(repr(self.scalar), repr(self.vector))
+        return f"_Quaternion({repr(self.scalar)}, {repr(self.vector)})"
 
     @classmethod
     def rotate_from_to(cls, r1, r2):