From a323b2543449d33ba3696dfbfa968167d4f2749b Mon Sep 17 00:00:00 2001
From: jbrockmendel <jbrockmendel@gmail.com>
Date: Wed, 22 Jan 2020 06:16:45 -0800
Subject: [PATCH] Backport PR #31017: REG: restore format_type attr

---
 pandas/io/pytables.py                  |  2 ++
 pandas/tests/io/pytables/test_store.py | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/pandas/io/pytables.py b/pandas/io/pytables.py
index d61d1cf7f0257..4f12c0225bd2d 100644
--- a/pandas/io/pytables.py
+++ b/pandas/io/pytables.py
@@ -2474,6 +2474,7 @@ class Fixed:
         """
 
     pandas_kind: str
+    format_type: str = "fixed"  # GH#30962 needed by dask
     obj_type: Type[Union[DataFrame, Series]]
     ndim: int
     encoding: str
@@ -3132,6 +3133,7 @@ class Table(Fixed):
         """
 
     pandas_kind = "wide_table"
+    format_type: str = "table"  # GH#30962 needed by dask
     table_type: str
     levels = 1
     is_table = True
diff --git a/pandas/tests/io/pytables/test_store.py b/pandas/tests/io/pytables/test_store.py
index 64c4ad800f49d..f56d042093886 100644
--- a/pandas/tests/io/pytables/test_store.py
+++ b/pandas/tests/io/pytables/test_store.py
@@ -64,6 +64,16 @@
 
 @pytest.mark.single
 class TestHDFStore:
+    def test_format_type(self, setup_path):
+        df = pd.DataFrame({"A": [1, 2]})
+        with ensure_clean_path(setup_path) as path:
+            with HDFStore(path) as store:
+                store.put("a", df, format="fixed")
+                store.put("b", df, format="table")
+
+                assert store.get_storer("a").format_type == "fixed"
+                assert store.get_storer("b").format_type == "table"
+
     def test_format_kwarg_in_constructor(self, setup_path):
         # GH 13291