matplotlib · ksunden · Jul 15, 2023 · Jun 23, 2023 · tacaswell · Jul 13, 2023
diff --git a/doc/users/next_whats_new/mathtext_delimiters.rst b/doc/users/next_whats_new/mathtext_delimiters.rst
@@ -0,0 +1,14 @@
+``mathtext`` has more sizable delimiters
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ``\lgroup`` and ``\rgroup`` sizable delimiters have been added.
+
+The following delimiter names have been supported earlier, but can now be sized with
+``\left`` and ``\right``:
+
+* ``\lbrace``, ``\rbrace``, ``\leftbrace``, and ``\rightbrace``
+* ``\lbrack`` and ``\rbrack``
+* ``\leftparen`` and ``\rightparen``
+
+There are really no obvious advantages in using these.
+Instead, they are are added for completeness.
diff --git a/lib/matplotlib/_mathtext.py b/lib/matplotlib/_mathtext.py
@@ -1808,8 +1808,12 @@ class _MathStyle(enum.Enum):
     _ambi_delims = set(r"""
       | \| / \backslash \uparrow \downarrow \updownarrow \Uparrow
       \Downarrow \Updownarrow . \vert \Vert""".split())
-    _left_delims = set(r"( [ \{ < \lfloor \langle \lceil".split())
-    _right_delims = set(r") ] \} > \rfloor \rangle \rceil".split())
+    _left_delims = set(r"""
+      ( [ \{ < \lfloor \langle \lceil \lbrace \leftbrace \lbrack \leftparen \lgroup
+      """.split())
+    _right_delims = set(r"""
+      ) ] \} > \rfloor \rangle \rceil \rbrace \rightbrace \rbrack \rightparen \rgroup
+      """.split())
     _delims = _left_delims | _right_delims | _ambi_delims
 
     _small_greek = set([unicodedata.name(chr(i)).split()[-1].lower() for i in

diff --git a/lib/matplotlib/_mathtext_data.py b/lib/matplotlib/_mathtext_data.py
@@ -957,6 +957,8 @@
     'cwopencirclearrow'        : 8635,
     'geqq'                     : 8807,
     'rightleftarrows'          : 8644,
+    'lgroup'                   : 0x27EE,
+    'rgroup'                   : 0x27EF,
     'aa'                       : 229,
     'ac'                       : 8766,
     'ae'                       : 230,
@@ -1016,7 +1018,7 @@
     'leftparen'                : 40,
     'rightparen'               : 41,
     'bigoplus'                 : 10753,
-    'leftbrace'                : 124,
+    'leftbrace'                : 123,
     'rightbrace'               : 125,
     'jmath'                    : 567,
     'bigodot'                  : 10752,

diff --git a/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext1_dejavusans_06.png b/lib/matplotlib/tests/baseline_images/test_mathtext/mathtext1_dejavusans_06.png
diff --git a/lib/matplotlib/tests/test_mathtext.py b/lib/matplotlib/tests/test_mathtext.py
@@ -135,6 +135,7 @@
     r'$1.$ $2.$ $19680801.$ $a.$ $b.$ $mpl.$',
     r'$\text{text}_{\text{sub}}^{\text{sup}} + \text{\$foo\$} + \frac{\text{num}}{\mathbf{\text{den}}}\text{with space, curly brackets \{\}, and dash -}$',
     r'$\boldsymbol{abcde} \boldsymbol{+} \boldsymbol{\Gamma + \Omega} \boldsymbol{01234} \boldsymbol{\alpha * \beta}$',
+    r'$\left\lbrace\frac{\left\lbrack A^b_c\right\rbrace}{\left\leftbrace D^e_f \right\rbrack}\right\rightbrace\ \left\leftparen\max_{x} \left\lgroup \frac{A}{B}\right\rgroup \right\rightparen$',
 ]
 
 digits = "0123456789"