Backport PR #41806 on branch 1.2.x" (#41835)

doc/source/whatsnew/v1.2.5.rst

@@ -18,6 +18,7 @@ Fixed regressions
 - Fixed regression in :meth:`DataFrame.sum` and :meth:`DataFrame.prod` when ``min_count`` and ``numeric_only`` are both given (:issue:`41074`)
 - Regression in :func:`read_csv` when using ``memory_map=True`` with an non-UTF8 encoding (:issue:`40986`)
 - Regression in :meth:`DataFrame.replace` and :meth:`Series.replace` when the values to replace is a NumPy float array (:issue:`40371`)
+- Regression in :func:`ExcelFile` when a corrupt file is opened but not closed (:issue:`41778`)
 
 .. ---------------------------------------------------------------------------
 

pandas/io/excel/_base.py

@@ -388,7 +388,11 @@ def __init__(self, filepath_or_buffer, storage_options: StorageOptions = None):
         elif hasattr(self.handles.handle, "read"):
             # N.B. xlrd.Book has a read attribute too
             self.handles.handle.seek(0)
-            self.book = self.load_workbook(self.handles.handle)
+            try:
+                self.book = self.load_workbook(self.handles.handle)
+            except Exception:
+                self.close()
+                raise
         elif isinstance(self.handles.handle, bytes):
             self.book = self.load_workbook(BytesIO(self.handles.handle))
         else:
@@ -406,6 +410,11 @@ def load_workbook(self, filepath_or_buffer):
         pass
 
     def close(self):
+        if hasattr(self, "book") and hasattr(self.book, "close"):
+            # pyxlsb: opens a TemporaryFile
+            # openpyxl: https://stackoverflow.com/questions/31416842/
+            #     openpyxl-does-not-close-excel-workbook-in-read-only-mode
+            self.book.close()
         self.handles.close()
 
     @property

pandas/io/excel/_openpyxl.py

@@ -487,12 +487,6 @@ def load_workbook(self, filepath_or_buffer: FilePathOrBuffer):
             filepath_or_buffer, read_only=True, data_only=True, keep_links=False
         )
 
-    def close(self):
-        # https://stackoverflow.com/questions/31416842/
-        #  openpyxl-does-not-close-excel-workbook-in-read-only-mode
-        self.book.close()
-        super().close()
-
     @property
     def sheet_names(self) -> List[str]:
         return self.book.sheetnames

pandas/tests/io/excel/test_readers.py

@@ -1,6 +1,7 @@
 from datetime import datetime, time
 from functools import partial
 import os
+from pathlib import Path
 from urllib.error import URLError
 from zipfile import BadZipFile
 
@@ -1273,3 +1274,21 @@ def test_read_datetime_multiindex(self, engine, read_ext):
         expected = DataFrame([], columns=expected_column_index)
 
         tm.assert_frame_equal(expected, actual)
+
+    def test_corrupt_files_closed(self, request, engine, read_ext):
+        # GH41778
+        errors = (BadZipFile, ValueError)
+        if engine is None:
+            pytest.skip()
+        elif engine == "xlrd":
+            import xlrd
+
+            errors = (BadZipFile, ValueError, xlrd.biffh.XLRDError)
+
+        with tm.ensure_clean(f"corrupt{read_ext}") as file:
+            Path(file).write_text("corrupt")
+            with tm.assert_produces_warning(False):
+                try:
+                    pd.ExcelFile(file, engine=engine)
+                except errors:
+                    pass