Deprecate using xlrd engine

pandas/io/excel/_base.py

@@ -3,6 +3,7 @@
 from io import BytesIO
 import os
 from textwrap import fill
+import warnings
 
 from pandas._config import config
 
@@ -780,7 +781,7 @@ def close(self):
 class ExcelFile:
     """
     Class for parsing tabular excel sheets into DataFrame objects.
-    Uses xlrd. See read_excel for more documentation
+    Uses xlrd, openpyxl or odf. See read_excel for more documentation
 
     Parameters
     ----------
@@ -802,6 +803,11 @@ class ExcelFile:
     def __init__(self, io, engine=None):
         if engine is None:
             engine = "xlrd"
+            warnings.warn(
+                'The Excel reader engine will default to "openpyxl" in the future. \
+                 Specify engine="openpyxl" to suppress this warning.',
+                FutureWarning,
+            )
         if engine not in self._engines:
             raise ValueError(f"Unknown engine: {engine}")
 

pandas/tests/io/excel/test_xlrd.py

@@ -1,3 +1,5 @@
+import warnings
+
 import pytest
 
 import pandas as pd
@@ -24,7 +26,6 @@ def test_read_xlrd_book(read_ext, frame):
     with tm.ensure_clean(read_ext) as pth:
         df.to_excel(pth, sheet_name)
         book = xlrd.open_workbook(pth)
-
         with ExcelFile(book, engine=engine) as xl:
             result = pd.read_excel(xl, sheet_name, index_col=0)
             tm.assert_frame_equal(df, result)
@@ -36,6 +37,24 @@ def test_read_xlrd_book(read_ext, frame):
 # TODO: test for openpyxl as well
 def test_excel_table_sheet_by_index(datapath, read_ext):
     path = datapath("io", "data", "excel", "test1{}".format(read_ext))
-    with pd.ExcelFile(path) as excel:
-        with pytest.raises(xlrd.XLRDError):
-            pd.read_excel(excel, "asdf")
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore")
+        with pd.ExcelFile(path) as excel:
+            with pytest.raises(xlrd.XLRDError):
+                pd.read_excel(excel, "asdf")
+
+
+# See issue #29375
+def test_excel_file_warning_with_default_engine(datapath):
+    path = datapath("io", "data", "excel", "test1.xls")
+    with warnings.catch_warnings(record=True) as w:
+        pd.ExcelFile(path)
+        assert "default to \"openpyxl\" in the future." in str(w[-1].message)        
+
+
+# See issue #29375
+def test_read_excel_warning_with_default_engine(tmpdir, datapath):
+    path = datapath("io", "data", "excel", "test1.xls")
+    with warnings.catch_warnings(record=True) as w:
+        pd.read_excel(path, "Sheet1")
+        assert "default to \"openpyxl\" in the future." in str(w[-1].message)