REF: dataframe formatters/outputs

pandas/core/frame.py

@@ -786,10 +786,8 @@ def _repr_html_(self) -> Optional[str]:
                 max_cols=max_cols,
                 show_dimensions=show_dimensions,
                 decimal=".",
-                table_id=None,
-                render_links=False,
             )
-            return formatter.to_html(notebook=True)
+            return fmt.DataFrameRenderer(formatter).to_html(notebook=True)
         else:
             return None
 
@@ -872,9 +870,10 @@ def to_string(
                 max_cols=max_cols,
                 show_dimensions=show_dimensions,
                 decimal=decimal,
-                line_width=line_width,
             )
-            return formatter.to_string(buf=buf, encoding=encoding)
+            return fmt.DataFrameRenderer(formatter).to_string(
+                buf=buf, encoding=encoding, line_width=line_width,
+            )
 
     # ----------------------------------------------------------------------
 
@@ -2467,29 +2466,29 @@ def to_html(
             columns=columns,
             col_space=col_space,
             na_rep=na_rep,
+            header=header,
+            index=index,
             formatters=formatters,
             float_format=float_format,
+            bold_rows=bold_rows,
             sparsify=sparsify,
             justify=justify,
             index_names=index_names,
-            header=header,
-            index=index,
-            bold_rows=bold_rows,
             escape=escape,
+            decimal=decimal,
             max_rows=max_rows,
             max_cols=max_cols,
             show_dimensions=show_dimensions,
-            decimal=decimal,
-            table_id=table_id,
-            render_links=render_links,
         )
         # TODO: a generic formatter wld b in DataFrameFormatter
-        return formatter.to_html(
+        return fmt.DataFrameRenderer(formatter).to_html(
             buf=buf,
             classes=classes,
             notebook=notebook,
             border=border,
             encoding=encoding,
+            table_id=table_id,
+            render_links=render_links,
         )
 
     # ----------------------------------------------------------------------

pandas/core/generic.py

@@ -4,7 +4,6 @@
 from datetime import timedelta
 import functools
 import gc
-from io import StringIO
 import json
 import operator
 import pickle
@@ -106,7 +105,11 @@
 from pandas.core.window import Expanding, ExponentialMovingWindow, Rolling, Window
 
 from pandas.io.formats import format as fmt
-from pandas.io.formats.format import DataFrameFormatter, format_percentiles
+from pandas.io.formats.format import (
+    DataFrameFormatter,
+    DataFrameRenderer,
+    format_percentiles,
+)
 from pandas.io.formats.printing import pprint_thing
 
 if TYPE_CHECKING:
@@ -3127,7 +3130,7 @@ def to_latex(
             escape=escape,
             decimal=decimal,
         )
-        return formatter.to_latex(
+        return DataFrameRenderer(formatter).to_latex(
             buf=buf,
             column_format=column_format,
             longtable=longtable,
@@ -3160,7 +3163,7 @@ def to_csv(
         date_format: Optional[str] = None,
         doublequote: bool_t = True,
         escapechar: Optional[str] = None,
-        decimal: Optional[str] = ".",
+        decimal: str = ".",
         errors: str = "strict",
         storage_options: StorageOptions = None,
     ) -> Optional[str]:
@@ -3318,39 +3321,33 @@ def to_csv(
         """
         df = self if isinstance(self, ABCDataFrame) else self.to_frame()
 
-        from pandas.io.formats.csvs import CSVFormatter
+        formatter = DataFrameFormatter(
+            frame=df,
+            header=header,
+            index=index,
+            na_rep=na_rep,
+            float_format=float_format,
+            decimal=decimal,
+        )
 
-        formatter = CSVFormatter(
-            df,
+        return DataFrameRenderer(formatter).to_csv(
             path_or_buf,
             line_terminator=line_terminator,
             sep=sep,
             encoding=encoding,
             errors=errors,
             compression=compression,
             quoting=quoting,
-            na_rep=na_rep,
-            float_format=float_format,
-            cols=columns,
-            header=header,
-            index=index,
+            columns=columns,
             index_label=index_label,
             mode=mode,
             chunksize=chunksize,
             quotechar=quotechar,
             date_format=date_format,
             doublequote=doublequote,
             escapechar=escapechar,
-            decimal=decimal,
             storage_options=storage_options,
         )
-        formatter.save()
-
-        if path_or_buf is None:
-            assert isinstance(formatter.path_or_buf, StringIO)
-            return formatter.path_or_buf.getvalue()
-
-        return None
 
     # ----------------------------------------------------------------------
     # Lookup Caching

pandas/io/formats/csvs.py

@@ -5,7 +5,7 @@
 import csv as csvlib
 from io import StringIO, TextIOWrapper
 import os
-from typing import Any, Dict, Hashable, Iterator, List, Optional, Sequence, Union
+from typing import Any, Dict, Iterator, List, Optional, Sequence
 
 import numpy as np
 
@@ -29,19 +29,16 @@
 from pandas.core.indexes.api import Index
 
 from pandas.io.common import get_filepath_or_buffer, get_handle
+from pandas.io.formats.format import DataFrameFormatter
 
 
 class CSVFormatter:
     def __init__(
         self,
-        obj,
+        formatter: DataFrameFormatter,
         path_or_buf: Optional[FilePathOrBuffer[str]] = None,
         sep: str = ",",
-        na_rep: str = "",
-        float_format: Optional[str] = None,
         cols: Optional[Sequence[Label]] = None,
-        header: Union[bool, Sequence[Hashable]] = True,
-        index: bool = True,
         index_label: Optional[IndexLabel] = None,
         mode: str = "w",
         encoding: Optional[str] = None,
@@ -54,10 +51,11 @@ def __init__(
         date_format: Optional[str] = None,
         doublequote: bool = True,
         escapechar: Optional[str] = None,
-        decimal=".",
         storage_options: StorageOptions = None,
     ):
-        self.obj = obj
+        self.fmt = formatter
+
+        self.obj = self.fmt.frame
 
         self.encoding = encoding or "utf-8"
 
@@ -79,11 +77,11 @@ def __init__(
         self.mode = ioargs.mode
 
         self.sep = sep
-        self.na_rep = na_rep
-        self.float_format = float_format
-        self.decimal = decimal
-        self.header = header
-        self.index = index
+        self.na_rep = self.fmt.na_rep
+        self.float_format = self.fmt.float_format
+        self.decimal = self.fmt.decimal
+        self.header = self.fmt.header
+        self.index = self.fmt.index
         self.index_label = index_label
         self.errors = errors
         self.quoting = quoting or csvlib.QUOTE_MINIMAL
@@ -161,7 +159,12 @@ def _refine_cols(self, cols: Optional[Sequence[Label]]) -> Sequence[Label]:
 
         # update columns to include possible multiplicity of dupes
         # and make sure sure cols is just a list of labels
-        cols = self.obj.columns
+
+        # Ignore mypy error
+        # Incompatible types in assignment
+        # (expression has type "Index",
+        # variable has type "Optional[Sequence[Optional[Hashable]]]")  [assignment]
+        cols = self.obj.columns  # type: ignore[assignment]
         if isinstance(cols, ABCIndexClass):
             return cols._format_native_types(**self._number_format)
         else: