Reapply "Add test for iterating over batches in DataFrame"

This reverts commit d997c70.

Author: kosiew

python/tests/test_dataframe.py

@@ -1582,6 +1582,18 @@ def test_empty_to_arrow_table(df):
     assert set(pyarrow_table.column_names) == {"a", "b", "c"}
 
 
+def test_iter_batches_dataframe(fail_collect):
+    ctx = SessionContext()
+
+    batch1 = pa.record_batch([pa.array([1])], names=["a"])
+    batch2 = pa.record_batch([pa.array([2])], names=["a"])
+    df = ctx.create_dataframe([[batch1], [batch2]])
+
+    expected = [batch1, batch2]
+    for got, exp in zip(df, expected):
+        assert got.equals(exp)
+
+
 def test_arrow_c_stream_to_table(fail_collect):
     ctx = SessionContext()