added test for round-trip with a deeply nested structure

Author: zpks

bindings/python/test/test_arrow.py

@@ -32,6 +32,7 @@
     date64,
     decimal256,
     field,
+    float64,
     int32,
     int64,
     large_list,
@@ -333,8 +334,6 @@ def test_write_schema_validation(self):
         with self.assertRaises(ValueError):
             self.round_trip(data, Schema(schema))
 
-
-
     def test_date_types(self):
         schema, data = self._create_data()
         self.round_trip(data, Schema(schema))
@@ -418,7 +417,46 @@ def inner(i):
         return schema, Table.from_pydict(raw_data, ArrowSchema(schema))
 
     def test_write_nested_schema_validation(self):
-        schema, data = self._create_nested_data(nested_elem=True)
+        raw_data = {
+            "_id": [1, 2],
+            "top": [
+                {
+                    "middle": {
+                        "value": "string_1",
+                        "bottom": [
+                            {"event": datetime(2012, 1, 1), "value": 1.1},
+                            {"event": datetime(2014, 1, 1), "value": 1.2},
+                        ],
+                    }
+                },
+                {
+                    "middle": {
+                        "value": "string_2",
+                        "bottom": [
+                            {"event": datetime(2013, 1, 1), "value": 1.2},
+                            {"event": datetime(2019, 1, 1), "value": 1.5},
+                        ],
+                    }
+                },
+            ],
+        }
+
+        schema = {
+            "_id": int64(),
+            "top": struct(
+                {
+                    "middle": struct(
+                        {
+                            "value": string(),
+                            "bottom": list_(struct({"event": timestamp("ms"), "value": float64()})),
+                        }
+                    )
+                }
+            ),
+        }
+
+        data = Table.from_pydict(raw_data, ArrowSchema(schema))
+
         self.round_trip(data, Schema(schema))
 
     def test_parquet(self):

bindings/python/test/test_schema.py

@@ -76,7 +76,7 @@ def test_from_arrow_units(self):
 
     def test_nested_projection(self):
         schema = Schema({"_id": int64(), "obj": {"a": int64(), "b": int64()}})
-        self.assertEqual(schema._get_projection(), {"_id": True, "obj": {"a": True, "b": True}})
+        self.assertEqual(schema._get_projection(), {"_id": True, "obj.a": True, "obj.b": True})
 
     def test_list_projection(self):
         schema = Schema(
@@ -85,7 +85,7 @@ def test_list_projection(self):
                 "list": list_(struct([field("a", int64()), field("b", int64())])),
             }
         )
-        self.assertEqual(schema._get_projection(), {"_id": True, "list": {"a": True, "b": True}})
+        self.assertEqual(schema._get_projection(), {"_id": True, "list.a": True, "list.b": True})
 
     def test_list_of_list_projection(self):
         schema = Schema(
@@ -94,14 +94,14 @@ def test_list_of_list_projection(self):
                 "list": list_(list_(struct([field("a", int64()), field("b", int64())]))),
             }
         )
-        self.assertEqual(schema._get_projection(), {"_id": True, "list": {"a": True, "b": True}})
+        self.assertEqual(schema._get_projection(), {"_id": True, "list.a": True, "list.b": True})
 
     def test_py_list_projection(self):
         schema = Schema(
             {"_id": ObjectId, "list": [(struct([field("a", int64()), field("b", float64())]))]}
         )
 
-        self.assertEqual(schema._get_projection(), {"_id": True, "list": {"a": True, "b": True}})
+        self.assertEqual(schema._get_projection(), {"_id": True, "list.a": True, "list.b": True})
 
     def test_py_list_with_multiple_fields_raises(self):
         with pytest.raises(