ENH: styler.render.encoding option (pandas-dev#43177)

Author: attack68

doc/source/user_guide/options.rst

@@ -489,6 +489,7 @@ styler.sparse.columns                   True         "Sparsify" MultiIndex displ
                                                      in Styler output.
 styler.render.max_elements              262144       Maximum number of datapoints that Styler will render
                                                      trimming either rows, columns or both to fit.
+styler.render.encoding                  utf-8        Default encoding for output HTML or LaTeX files.
 styler.format.formatter                 None         Object to specify formatting functions to ``Styler.format``.
 styler.format.na_rep                    None         String representation for missing data.
 styler.format.precision                 6            Precision to display floating point and complex numbers.

doc/source/whatsnew/v1.4.0.rst

@@ -75,7 +75,7 @@ Styler
   - :meth:`.Styler.to_latex` introduces keyword argument ``environment``, which also allows a specific "longtable" entry through a separate jinja2 template (:issue:`41866`).
   - :meth:`.Styler.to_html` introduces keyword arguments ``sparse_index`` and ``sparse_columns`` (:issue:`41946`)
   - Keyword argument ``level`` is added to :meth:`.Styler.hide_index` and :meth:`.Styler.hide_columns` for optionally controlling hidden levels in a MultiIndex (:issue:`25475`)
-  - Global options have been extended to configure default ``Styler`` properties including formatting options (:issue:`41395`)
+  - Global options have been extended to configure default ``Styler`` properties including formatting and encoding options (:issue:`41395`)
 
 There are also bug fixes and deprecations listed below.
 

pandas/core/config_init.py

@@ -793,6 +793,11 @@ def register_converter_cb(key):
     A formatter object to be used as default within ``Styler.format``.
 """
 
+styler_encoding = """
+: str
+    The encoding used for output HTML and LaTeX files.
+"""
+
 with cf.config_prefix("styler"):
     cf.register_option("sparse.index", True, styler_sparse_index_doc, validator=bool)
 
@@ -807,6 +812,8 @@ def register_converter_cb(key):
         validator=is_nonnegative_int,
     )
 
+    cf.register_option("render.encoding", "utf-8", styler_encoding, validator=is_str)
+
     cf.register_option("format.decimal", ".", styler_decimal, validator=is_str)
 
     cf.register_option(

pandas/io/formats/style.py

@@ -526,8 +526,9 @@ def to_latex(
             rendered.
 
             .. versionadded:: 1.4.0
-        encoding : str, default "utf-8"
-            Character encoding setting.
+        encoding : str, optional
+            Character encoding setting. Defaults
+            to ``pandas.options.styler.render.encoding`` value of "utf-8".
         convert_css : bool, default False
             Convert simple cell-styles from CSS to LaTeX format. Any CSS not found in
             conversion table is dropped. A style can be forced by adding option
@@ -849,7 +850,10 @@ def to_latex(
             convert_css=convert_css,
         )
 
-        return save_to_buffer(latex, buf=buf, encoding=encoding)
+        encoding = encoding or get_option("styler.render.encoding")
+        return save_to_buffer(
+            latex, buf=buf, encoding=None if buf is None else encoding
+        )
 
     def to_html(
         self,
@@ -898,8 +902,8 @@ def to_html(
 
             .. versionadded:: 1.4.0
         encoding : str, optional
-            Character encoding setting for file output, and HTML meta tags,
-            defaults to "utf-8" if None.
+            Character encoding setting for file output, and HTML meta tags.
+            Defaults to ``pandas.options.styler.render.encoding`` value of "utf-8".
         doctype_html : bool, default False
             Whether to output a fully structured HTML file including all
             HTML elements, or just the core ``<style>`` and ``<table>`` elements.
@@ -934,12 +938,13 @@ def to_html(
         if sparse_columns is None:
             sparse_columns = get_option("styler.sparse.columns")
 
+        encoding = encoding or get_option("styler.render.encoding")
         # Build HTML string..
         html = obj._render_html(
             sparse_index=sparse_index,
             sparse_columns=sparse_columns,
             exclude_styles=exclude_styles,
-            encoding=encoding if encoding else "utf-8",
+            encoding=encoding,
             doctype_html=doctype_html,
             **kwargs,
         )

pandas/tests/io/formats/style/test_html.py

@@ -191,6 +191,14 @@ def test_doctype(styler):
     assert "<head>" not in result
 
 
+def test_doctype_encoding(styler):
+    with option_context("styler.render.encoding", "ASCII"):
+        result = styler.to_html(doctype_html=True)
+        assert '<meta charset="ASCII">' in result
+        result = styler.to_html(doctype_html=True, encoding="ANSI")
+        assert '<meta charset="ANSI">' in result
+
+
 def test_block_names(tpl_style, tpl_table):
     # catch accidental removal of a block
     expected_style = {