DEPR: Nonkeyword arguments in to_latex

doc/source/whatsnew/v2.2.0.rst

@@ -93,6 +93,7 @@ Other API changes
 Deprecations
 ~~~~~~~~~~~~
 - Deprecated allowing non-keyword arguments in :meth:`DataFrame.to_hdf` except ``path_or_buf``. (:issue:`54229`)
+- Deprecated allowing non-keyword arguments in :meth:`DataFrame.to_latex` except ``buf``. (:issue:`54229`)
 - Deprecated allowing non-keyword arguments in :meth:`DataFrame.to_pickle` except ``path``. (:issue:`54229`)
 -
 

pandas/core/generic.py

@@ -3306,6 +3306,9 @@ def to_latex(
         ...
 
     @final
+    @deprecate_nonkeyword_arguments(
+        version="3.0", allowed_args=["self", "buf"], name="to_latex"
+    )
     def to_latex(
         self,
         buf: FilePath | WriteBuffer[str] | None = None,

pandas/tests/io/formats/test_to_latex.py

@@ -187,6 +187,22 @@ def test_to_latex_midrule_location(self):
         )
         assert result == expected
 
+    def test_to_latex_pos_args_deprecation(self):
+        # GH-54229
+        df = DataFrame(
+            {
+                "name": ["Raphael", "Donatello"],
+                "age": [26, 45],
+                "height": [181.23, 177.65],
+            }
+        )
+        msg = (
+            r"Starting with pandas version 3.0 all arguments of to_latex except for "
+            r"the argument 'buf' will be keyword-only."
+        )
+        with tm.assert_produces_warning(FutureWarning, match=msg):
+            df.to_latex(None, None)
+
 
 class TestToLatexLongtable:
     def test_to_latex_empty_longtable(self):