BUG: fix is_named_tuple for objects that are not subclass of tuple #40682

pandas/core/dtypes/inference.py

@@ -315,7 +315,7 @@ def is_named_tuple(obj) -> bool:
  >>> is_named_tuple((1, 2))
  False
  """
- return isinstance(obj, tuple) and hasattr(obj, "_fields")
+ return isinstance(obj, abc.Sequence) and hasattr(obj, "_fields")
 
 
 def is_hashable(obj) -> bool:

pandas/tests/io/test_sql.py

@@ -2189,6 +2189,45 @@ def test_bigint_warning(self):
  with tm.assert_produces_warning(None):
  sql.read_sql_table("test_bigintwarning", self.conn)
 
+ def test_row_object_is_named_tuple(self):
+ # GH 40682
+ # Test for the is_named_tuple() function
+ # Placed here due to its usage of sqlalchemy
+
+ from sqlalchemy import (
+ Column,
+ Integer,
+ String,
+ )
+ from sqlalchemy.orm import sessionmaker
+
+ if _gt14():
+ from sqlalchemy.orm import declarative_base
+ else:
+ from sqlalchemy.ext.declarative import declarative_base
+
+ BaseModel = declarative_base()
+
+ class Test(BaseModel):
+ __tablename__ = "test_Frame"
+ id = Column(Integer, primary_key=True)
+ foo = Column(String(50))
+
+ BaseModel.metadata.create_all(self.conn)
+ Session = sessionmaker(bind=self.conn)
+ session = Session()
+
+ df = DataFrame({"id": [0, 1], "foo": ["hello", "world"]})
+ df.to_sql("test_Frame", con=self.conn, index=False, if_exists="replace")
+
+ session.commit()
+ foo = session.query(Test.id, Test.foo)
+ print(foo)
+ df = DataFrame(foo)
+ session.close()
+
+ assert list(df.columns) == ["id", "foo"]
+
 
 class _TestMySQLAlchemy:
  """