ENH: Add StataWriter 118 for unicode support

Add StataWriter with unicode support

Author: bashtage

doc/source/whatsnew/v1.0.0.rst

@@ -207,7 +207,7 @@ Other enhancements
 - The ``partition_cols`` argument in :meth:`DataFrame.to_parquet` now accepts a string (:issue:`27117`)
 - :func:`to_parquet` now appropriately handles the ``schema`` argument for user defined schemas in the pyarrow engine. (:issue: `30270`)
 - DataFrame constructor preserve `ExtensionArray` dtype with `ExtensionArray` (:issue:`11363`)
-
+- Added new writer for exporting Stata dta files in version 118, ``StataWriter118``.  This format supports exporting strings containing Unicode characters (:issue:`23573`)
 
 Build Changes
 ^^^^^^^^^^^^^

pandas/core/frame.py

@@ -1926,14 +1926,17 @@ def to_stata(
         >>> df.to_stata('animals.dta')  # doctest: +SKIP
         """
         kwargs = {}
-        if version not in (114, 117):
-            raise ValueError("Only formats 114 and 117 supported.")
+        if version not in (114, 117, 118):
+            raise ValueError("Only formats 114, 117 and 118 are supported.")
         if version == 114:
             if convert_strl is not None:
-                raise ValueError("strl support is only available when using format 117")
+                raise ValueError("strl is not supported in format 114")
             from pandas.io.stata import StataWriter as statawriter
         else:
-            from pandas.io.stata import StataWriter117 as statawriter
+            if version == 117:
+                from pandas.io.stata import StataWriter117 as statawriter
+            else:
+                from pandas.io.stata import StataWriter118 as statawriter
 
             kwargs["convert_strl"] = convert_strl