DEPR: Series.to_csv signature change (#29809)

Author: jbrockmendel

pandas/core/series.py

@@ -4400,101 +4400,6 @@ def between(self, left, right, inclusive=True):
 
         return lmask & rmask
 
-    @Appender(generic.NDFrame.to_csv.__doc__)
-    def to_csv(self, *args, **kwargs):
-
-        names = [
-            "path_or_buf",
-            "sep",
-            "na_rep",
-            "float_format",
-            "columns",
-            "header",
-            "index",
-            "index_label",
-            "mode",
-            "encoding",
-            "compression",
-            "quoting",
-            "quotechar",
-            "line_terminator",
-            "chunksize",
-            "date_format",
-            "doublequote",
-            "escapechar",
-            "decimal",
-        ]
-
-        old_names = [
-            "path_or_buf",
-            "index",
-            "sep",
-            "na_rep",
-            "float_format",
-            "header",
-            "index_label",
-            "mode",
-            "encoding",
-            "compression",
-            "date_format",
-            "decimal",
-        ]
-
-        if "path" in kwargs:
-            warnings.warn(
-                "The signature of `Series.to_csv` was aligned "
-                "to that of `DataFrame.to_csv`, and argument "
-                "'path' will be renamed to 'path_or_buf'.",
-                FutureWarning,
-                stacklevel=2,
-            )
-            kwargs["path_or_buf"] = kwargs.pop("path")
-
-        if len(args) > 1:
-            # Either "index" (old signature) or "sep" (new signature) is being
-            # passed as second argument (while the first is the same)
-            maybe_sep = args[1]
-
-            if not (isinstance(maybe_sep, str) and len(maybe_sep) == 1):
-                # old signature
-                warnings.warn(
-                    "The signature of `Series.to_csv` was aligned "
-                    "to that of `DataFrame.to_csv`. Note that the "
-                    "order of arguments changed, and the new one "
-                    "has 'sep' in first place, for which \"{}\" is "
-                    "not a valid value. The old order will cease to "
-                    "be supported in a future version. Please refer "
-                    "to the documentation for `DataFrame.to_csv` "
-                    "when updating your function "
-                    "calls.".format(maybe_sep),
-                    FutureWarning,
-                    stacklevel=2,
-                )
-                names = old_names
-
-        pos_args = dict(zip(names[: len(args)], args))
-
-        for key in pos_args:
-            if key in kwargs:
-                raise ValueError(
-                    "Argument given by name ('{}') and position "
-                    "({})".format(key, names.index(key))
-                )
-            kwargs[key] = pos_args[key]
-
-        if kwargs.get("header", None) is None:
-            warnings.warn(
-                "The signature of `Series.to_csv` was aligned "
-                "to that of `DataFrame.to_csv`, and argument "
-                "'header' will change its default value from False "
-                "to True: please pass an explicit value to suppress "
-                "this warning.",
-                FutureWarning,
-                stacklevel=2,
-            )
-            kwargs["header"] = False  # Backwards compatibility.
-        return self.to_frame().to_csv(**kwargs)
-
     @Appender(generic._shared_docs["isna"] % _shared_doc_kwargs)
     def isna(self):
         return super().isna()

pandas/tests/io/test_compression.py

@@ -1,9 +1,7 @@
-import contextlib
 import os
 import subprocess
 import sys
 import textwrap
-import warnings
 
 import pytest
 
@@ -13,17 +11,6 @@
 import pandas.io.common as icom
 
 
-@contextlib.contextmanager
-def catch_to_csv_depr():
-    # Catching warnings because Series.to_csv has
-    # been deprecated. Remove this context when
-    # Series.to_csv has been aligned.
-
-    with warnings.catch_warnings(record=True):
-        warnings.simplefilter("ignore", FutureWarning)
-        yield
-
-
 @pytest.mark.parametrize(
     "obj",
     [
@@ -37,12 +24,11 @@ def catch_to_csv_depr():
 @pytest.mark.parametrize("method", ["to_pickle", "to_json", "to_csv"])
 def test_compression_size(obj, method, compression_only):
     with tm.ensure_clean() as path:
-        with catch_to_csv_depr():
-            getattr(obj, method)(path, compression=compression_only)
-            compressed_size = os.path.getsize(path)
-            getattr(obj, method)(path, compression=None)
-            uncompressed_size = os.path.getsize(path)
-            assert uncompressed_size > compressed_size
+        getattr(obj, method)(path, compression=compression_only)
+        compressed_size = os.path.getsize(path)
+        getattr(obj, method)(path, compression=None)
+        uncompressed_size = os.path.getsize(path)
+        assert uncompressed_size > compressed_size
 
 
 @pytest.mark.parametrize(
@@ -59,18 +45,16 @@ def test_compression_size(obj, method, compression_only):
 def test_compression_size_fh(obj, method, compression_only):
     with tm.ensure_clean() as path:
         f, handles = icom._get_handle(path, "w", compression=compression_only)
-        with catch_to_csv_depr():
-            with f:
-                getattr(obj, method)(f)
-                assert not f.closed
-            assert f.closed
-            compressed_size = os.path.getsize(path)
+        with f:
+            getattr(obj, method)(f)
+            assert not f.closed
+        assert f.closed
+        compressed_size = os.path.getsize(path)
     with tm.ensure_clean() as path:
         f, handles = icom._get_handle(path, "w", compression=None)
-        with catch_to_csv_depr():
-            with f:
-                getattr(obj, method)(f)
-                assert not f.closed
+        with f:
+            getattr(obj, method)(f)
+            assert not f.closed
         assert f.closed
         uncompressed_size = os.path.getsize(path)
         assert uncompressed_size > compressed_size

pandas/tests/series/test_io.py

@@ -25,24 +25,6 @@ def read_csv(self, path, **kwargs):
 
         return out
 
-    @pytest.mark.parametrize("arg", ["path", "header", "both"])
-    def test_to_csv_deprecation(self, arg, datetime_series):
-        # see gh-19715
-        with tm.ensure_clean() as path:
-            if arg == "path":
-                kwargs = dict(path=path, header=False)
-            elif arg == "header":
-                kwargs = dict(path_or_buf=path)
-            else:  # Both discrepancies match.
-                kwargs = dict(path=path)
-
-            with tm.assert_produces_warning(FutureWarning):
-                datetime_series.to_csv(**kwargs)
-
-                # Make sure roundtrip still works.
-                ts = self.read_csv(path)
-                tm.assert_series_equal(datetime_series, ts, check_names=False)
-
     def test_from_csv(self, datetime_series, string_series):
 
         with tm.ensure_clean() as path: