REF: move get_filepath_buffer into get_handle

doc/source/user_guide/io.rst

@@ -1024,17 +1024,18 @@ Writing CSVs to binary file objects
 
 .. versionadded:: 1.2.0
 
-``df.to_csv(..., mode="w+b")`` allows writing a CSV to a file object
-opened binary mode. For this to work, it is necessary that ``mode``
-contains a "b":
+``df.to_csv(..., mode="wb")`` allows writing a CSV to a file object
+opened binary mode. In most cases, it is not necessary to specify
+``mode`` as Pandas will auto-detect whether the file object is
+opened in text or binary mode.
 
 .. ipython:: python
 
    import io
 
    data = pd.DataFrame([0, 1, 2])
    buffer = io.BytesIO()
-   data.to_csv(buffer, mode="w+b", encoding="utf-8", compression="gzip")
+   data.to_csv(buffer, encoding="utf-8", compression="gzip")
 
 .. _io.float_precision:
 

doc/source/whatsnew/v1.2.0.rst

@@ -84,7 +84,8 @@ Support for binary file handles in ``to_csv``
 
 :meth:`to_csv` supports file handles in binary mode (:issue:`19827` and :issue:`35058`)
 with ``encoding`` (:issue:`13068` and :issue:`23854`) and ``compression`` (:issue:`22555`).
-``mode`` has to contain a ``b`` for binary handles to be supported.
+If Pandas does not automatically detect whether the file handle is opened in binary or text mode,
+it is necessary to provide ``mode="wb"``.
 
 For example:
 
@@ -94,7 +95,7 @@ For example:
 
    data = pd.DataFrame([0, 1, 2])
    buffer = io.BytesIO()
-   data.to_csv(buffer, mode="w+b", encoding="utf-8", compression="gzip")
+   data.to_csv(buffer, encoding="utf-8", compression="gzip")
 
 Support for short caption and table position in ``to_latex``
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -514,6 +515,7 @@ I/O
 - :func:`read_csv` was closing user-provided binary file handles when ``engine="c"`` and an ``encoding`` was requested (:issue:`36980`)
 - Bug in :meth:`DataFrame.to_hdf` was not dropping missing rows with ``dropna=True`` (:issue:`35719`)
 - Bug in :func:`read_html` was raising a ``TypeError`` when supplying a ``pathlib.Path`` argument to the ``io`` parameter (:issue:`37705`)
+- :meth:`to_excel` and :meth:`to_markdown` support writing to fsspec URLs such as S3 and Google Cloud Storage (:issue:`33987`)
 
 Plotting
 ^^^^^^^^

pandas/_typing.py

@@ -146,10 +146,5 @@
 CompressionOptions = Optional[Union[str, CompressionDict]]
 
 
-# let's bind types
-ModeVar = TypeVar("ModeVar", str, None, Optional[str])
-EncodingVar = TypeVar("EncodingVar", str, None, Optional[str])
-
-
 # type of float formatter in DataFrameFormatter
 FloatFormatType = Union[str, Callable, "EngFormatter"]

pandas/core/frame.py

@@ -157,7 +157,7 @@
 from pandas.core.series import Series
 from pandas.core.sorting import get_group_index, lexsort_indexer, nargsort
 
-from pandas.io.common import get_filepath_or_buffer
+from pandas.io.common import get_handle
 from pandas.io.formats import console, format as fmt
 from pandas.io.formats.info import DataFrameInfo
 import pandas.plotting
@@ -2301,10 +2301,10 @@ def to_markdown(
         result = tabulate.tabulate(self, **kwargs)
         if buf is None:
             return result
-        ioargs = get_filepath_or_buffer(buf, mode=mode, storage_options=storage_options)
-        assert not isinstance(ioargs.filepath_or_buffer, (str, mmap.mmap))
-        ioargs.filepath_or_buffer.writelines(result)
-        ioargs.close()
+
+        with get_handle(buf, mode, storage_options=storage_options) as handles:
+            assert not isinstance(handles.handle, (str, mmap.mmap))
+            handles.handle.writelines(result)
         return None
 
     @deprecate_kwarg(old_arg_name="fname", new_arg_name="path")

pandas/core/generic.py

@@ -3221,7 +3221,7 @@ def to_csv(
             File path or object, if None is provided the result is returned as
             a string.  If a non-binary file object is passed, it should be opened
             with `newline=''`, disabling universal newlines. If a binary
-            file object is passed, `mode` needs to contain a `'b'`.
+            file object is passed, `mode` might need to contain a `'b'`.
 
             .. versionchanged:: 0.24.0