Super/subscript

docs/user/text.rst

@@ -168,6 +168,8 @@ the theme color Accent 1.
     font.bold = True
     font.italic = None  # cause value to be inherited from theme
     font.color.theme_color = MSO_THEME_COLOR.ACCENT_1
+    font.superscript = True # sets superscript (baseline 30000)
+    font.subscript = True # sets subscript (baseline -25000), removes superscript (only 1 allowed at a time)
 
 If you prefer, you can set the font color to an absolute RGB value. Note that
 this will not change color when the theme is changed::

pptx/oxml/text.py

@@ -27,6 +27,7 @@
     ST_TextSpacingPoint,
     ST_TextTypeface,
     ST_TextWrappingType,
+    BaseIntType,
     XsdBoolean,
 )
 from pptx.oxml.xmlchemy import (
@@ -305,6 +306,7 @@ class CT_TextCharacterProperties(BaseOxmlElement):
     sz = OptionalAttribute("sz", ST_TextFontSize)
     b = OptionalAttribute("b", XsdBoolean)
     i = OptionalAttribute("i", XsdBoolean)
+    baseline = OptionalAttribute("baseline", BaseIntType)
     u = OptionalAttribute("u", MSO_TEXT_UNDERLINE_TYPE)
 
     def _new_gradFill(self):

pptx/text/text.py

@@ -339,6 +339,32 @@ def italic(self):
     def italic(self, value):
         self._rPr.i = value
 
+    @property
+    def superscript(self):
+        # baseline of 30000 means superscript
+        if self._rPr.baseline == 30000:
+            return True
+        return False
+
+    @superscript.setter
+    def superscript(self, value):
+        self._rPr.baseline = 0
+        if value:
+            self._rPr.baseline = 30000
+
+    @property
+    def subscript(self):
+        # baseline of -25000 means subscript
+        if self._rPr.baseline == -25000:
+            return True
+        return False
+
+    @subscript.setter
+    def subscript(self, value):
+        self._rPr.baseline = 0
+        if value:
+            self._rPr.baseline = -25000
+
     @property
     def language_id(self):
         """

tests/text/test_text.py

@@ -499,6 +499,24 @@ def it_can_change_its_italic_setting(self, italic_set_fixture):
         font.italic = new_value
         assert font._element.xml == expected_xml
 
+    def it_knows_its_superscript_setting(self, superscript_get_fixture):
+        font, expected_value = superscript_get_fixture
+        assert font.superscript == expected_value
+
+    def it_can_change_its_superscript_setting(self, superscript_set_fixture):
+        font, new_value, expected_xml = superscript_set_fixture
+        font.superscript = new_value
+        assert font._element.xml == expected_xml
+
+    def it_knows_its_subscript_setting(self, subscript_get_fixture):
+        font, expected_value = subscript_get_fixture
+        assert font.subscript == expected_value
+
+    def it_can_change_its_subscript_setting(self, subscript_set_fixture):
+        font, new_value, expected_xml = subscript_set_fixture
+        font.subscript = new_value
+        assert font._element.xml == expected_xml
+
     def it_knows_its_language_id(self, language_id_get_fixture):
         font, expected_value = language_id_get_fixture
         assert font.language_id == expected_value
@@ -585,6 +603,48 @@ def italic_set_fixture(self, request):
         expected_xml = xml(expected_rPr_cxml)
         return font, new_value, expected_xml
 
+    @pytest.fixture(
+        params=[("a:rPr{baseline=30000}", True), ("a:rPr{baseline=0}", False)]
+    )
+    def superscript_get_fixture(self, request):
+        rPr_cxml, expected_value = request.param
+        font = Font(element(rPr_cxml))
+        return font, expected_value
+
+    @pytest.fixture(
+        params=[
+            ("a:rPr", True, "a:rPr{baseline=30000}"),
+            ("a:rPr{baseline=30000}", False, "a:rPr{baseline=0}"),
+            ("a:rPr{baseline=-25000}", False, "a:rPr{baseline=0}"),
+        ]
+    )
+    def superscript_set_fixture(self, request):
+        rPr_cxml, new_value, expected_rPr_cxml = request.param
+        font = Font(element(rPr_cxml))
+        expected_xml = xml(expected_rPr_cxml)
+        return font, new_value, expected_xml
+
+    @pytest.fixture(
+        params=[("a:rPr{baseline=-25000}", True), ("a:rPr{baseline=0}", False)]
+    )
+    def subscript_get_fixture(self, request):
+        rPr_cxml, expected_value = request.param
+        font = Font(element(rPr_cxml))
+        return font, expected_value
+
+    @pytest.fixture(
+        params=[
+            ("a:rPr", True, "a:rPr{baseline=-25000}"),
+            ("a:rPr{baseline=30000}", False, "a:rPr{baseline=0}"),
+            ("a:rPr{baseline=-25000}", False, "a:rPr{baseline=0}"),
+        ]
+    )
+    def subscript_set_fixture(self, request):
+        rPr_cxml, new_value, expected_rPr_cxml = request.param
+        font = Font(element(rPr_cxml))
+        expected_xml = xml(expected_rPr_cxml)
+        return font, new_value, expected_xml
+
     @pytest.fixture(
         params=[
             ("a:rPr", MSO_LANGUAGE_ID.NONE),