ENH: Make to_csv('filename.csv.zip') compress the output

pandas/io/common.py

@@ -776,6 +776,11 @@ def __init__(
         self.archive_name = archive_name
         self.multiple_write_buffer: Optional[Union[StringIO, BytesIO]] = None
 
+        if archive_name is None and isinstance(file, (os.PathLike, str)):
+            archive_name = os.path.basename(file)
+            if archive_name.endswith(".zip"):
+                self.archive_name = archive_name[:-4]
+
         kwargs_zip: Dict[str, Any] = {"compression": zipfile.ZIP_DEFLATED}
         kwargs_zip.update(kwargs)
 

pandas/tests/io/formats/test_to_csv.py

@@ -1,6 +1,8 @@
 import io
 import os
+from pathlib import Path
 import sys
+from zipfile import ZipFile
 
 import numpy as np
 import pytest
@@ -541,15 +543,17 @@ def test_to_csv_compression_dict_no_method_raises(self):
     )
     def test_to_csv_zip_arguments(self, compression, archive_name):
         # GH 26023
-        from zipfile import ZipFile
-
         df = DataFrame({"ABC": [1]})
         with tm.ensure_clean("to_csv_archive_name.zip") as path:
             df.to_csv(
                 path, compression={"method": compression, "archive_name": archive_name}
             )
             with ZipFile(path) as zp:
-                expected_arcname = path if archive_name is None else archive_name
+                if archive_name is None:
+                    pth = Path(path)
+                    expected_arcname = pth.stem
+                else:
+                    expected_arcname = archive_name
                 expected_arcname = os.path.basename(expected_arcname)
                 assert len(zp.filelist) == 1
                 archived_file = os.path.basename(zp.filelist[0].filename)
@@ -644,6 +648,27 @@ def test_to_csv_encoding_binary_handle(self, mode):
                 handle.seek(0)
                 assert handle.read().startswith(b'\xef\xbb\xbf""')
 
+    @pytest.mark.parametrize(
+        "df,csv_name",
+        [
+            (
+                DataFrame({"a": [1, 2, 3, 4, 5], "b": [4, 5, 6, 7, 8]}),
+                "test_to_csv_zipped_content_name.csv",
+            )
+        ],
+    )
+    def test_to_csv_content_name_in_zipped_file(self, df, csv_name):
+        suffix_zip_name = csv_name + ".zip"
+        with tm.ensure_clean(suffix_zip_name) as pth:
+            # ensure_clean will add random str before suffix_zip_name,
+            # need Path.stem to get real file name
+            df.to_csv(pth)
+            pp = Path(pth)
+            with ZipFile(pth) as zf:
+                result = zf.filelist[0].filename
+                expected = pp.stem
+                assert result == expected
+
 
 def test_to_csv_iterative_compression_name(compression):
     # GH 38714