CLN: move GH21227 check to pandas/io/common.py

Author: ivanovmg

pandas/io/common.py

@@ -208,6 +208,21 @@ def get_filepath_or_buffer(
     # handle compression dict
     compression_method, compression = get_compression_method(compression)
     compression_method = infer_compression(filepath_or_buffer, compression_method)
+
+    # GH21227 internal compression is not used for non-binary handles.
+    if (
+        compression_method
+        and hasattr(filepath_or_buffer, "write")
+        and mode
+        and "b" not in mode
+    ):
+        warnings.warn(
+            "compression has no effect when passing a non-binary object as input.",
+            RuntimeWarning,
+            stacklevel=2,
+        )
+        compression_method = None
+
     compression = dict(compression, method=compression_method)
 
     # bz2 and xz do not write the byte order mark for utf-16 and utf-32

pandas/io/formats/csvs.py

@@ -6,7 +6,6 @@
 from io import StringIO, TextIOWrapper
 import os
 from typing import Generator, Hashable, List, Optional, Sequence, Union
-import warnings
 
 import numpy as np
 
@@ -59,6 +58,7 @@ def __init__(
         storage_options: StorageOptions = None,
     ):
         self.obj = obj
+
         self.encoding = encoding or "utf-8"
 
         if path_or_buf is None:
@@ -71,25 +71,13 @@ def __init__(
             mode=mode,
             storage_options=storage_options,
         )
+
         self.compression = ioargs.compression.pop("method")
         self.compression_args = ioargs.compression
         self.path_or_buf = ioargs.filepath_or_buffer
         self.should_close = ioargs.should_close
         self.mode = ioargs.mode
 
-        # GH21227 internal compression is not used for non-binary handles.
-        if (
-            self.compression
-            and hasattr(self.path_or_buf, "write")
-            and "b" not in self.mode
-        ):
-            warnings.warn(
-                "compression has no effect when passing a non-binary object as input.",
-                RuntimeWarning,
-                stacklevel=2,
-            )
-            self.compression = None
-
         self.sep = sep
         self.na_rep = na_rep
         self.float_format = float_format