ENH: add support for reading binary Excel files (#30519)

Closes gh-15914

Author: ftruzzi

doc/source/whatsnew/v1.0.0.rst

@@ -931,6 +931,7 @@ I/O
 - Bug in :class:`PythonParser` where str and bytes were being mixed when dealing with the decimal field (:issue:`29650`)
 - :meth:`read_gbq` now accepts ``progress_bar_type`` to display progress bar while the data downloads. (:issue:`29857`)
 - Bug in :func:`pandas.io.json.json_normalize` where a missing value in the location specified by `record_path` would raise a ``TypeError`` (:issue:`30148`)
+- :func:`read_excel` now accepts binary data (:issue:`15914`)
 
 Plotting
 ^^^^^^^^

pandas/io/excel/_base.py

@@ -40,7 +40,7 @@
 
 Parameters
 ----------
-io : str, ExcelFile, xlrd.Book, path object or file-like object
+io : str, bytes, ExcelFile, xlrd.Book, path object, or file-like object
     Any valid string path is acceptable. The string could be a URL. Valid
     URL schemes include http, ftp, s3, and file. For file URLs, a host is
     expected. A local file could be: ``file://localhost/path/to/table.xlsx``.
@@ -350,6 +350,8 @@ def __init__(self, filepath_or_buffer):
             self.book = self.load_workbook(filepath_or_buffer)
         elif isinstance(filepath_or_buffer, str):
             self.book = self.load_workbook(filepath_or_buffer)
+        elif isinstance(filepath_or_buffer, bytes):
+            self.book = self.load_workbook(BytesIO(filepath_or_buffer))
         else:
             raise ValueError(
                 "Must explicitly set engine if not passing in buffer or path for io."

pandas/tests/io/excel/test_readers.py

@@ -988,3 +988,13 @@ def test_conflicting_excel_engines(self, read_ext):
         with pd.ExcelFile("test1" + read_ext) as xl:
             with pytest.raises(ValueError, match=msg):
                 pd.read_excel(xl, engine="foo")
+
+    def test_excel_read_binary(self, engine, read_ext):
+        # GH 15914
+        expected = pd.read_excel("test1" + read_ext, engine=engine)
+
+        with open("test1" + read_ext, "rb") as f:
+            data = f.read()
+
+        actual = pd.read_excel(data, engine=engine)
+        tm.assert_frame_equal(expected, actual)