Answer by Yang Bo for Add variables to tuple

In Python 3, you can use * to create a new tuple of elements from the original tuple along with the new element.

>>> tuple1 = ("foo", "bar")>>> tuple2 = (*tuple1, "baz")>>> tuple2('foo', 'bar', 'baz')

The byte code is almost the same as tuple1 + ("baz",)

Python 3.7.5 (default, Oct 22 2019, 10:35:10) [Clang 10.0.1 (clang-1001.0.46.4)] on darwinType "help", "copyright", "credits" or "license" for more information.>>> def f():...     tuple1 = ("foo", "bar")...     tuple2 = (*tuple1, "baz")...     return tuple2... >>> def g():...     tuple1 = ("foo", "bar")...     tuple2 = tuple1 + ("baz",)...     return tuple2... >>> from dis import dis>>> dis(f)  2           0 LOAD_CONST               1 (('foo', 'bar'))              2 STORE_FAST               0 (tuple1)  3           4 LOAD_FAST                0 (tuple1)              6 LOAD_CONST               3 (('baz',))              8 BUILD_TUPLE_UNPACK       2             10 STORE_FAST               1 (tuple2)  4          12 LOAD_FAST                1 (tuple2)             14 RETURN_VALUE>>> dis(g)  2           0 LOAD_CONST               1 (('foo', 'bar'))              2 STORE_FAST               0 (tuple1)  3           4 LOAD_FAST                0 (tuple1)              6 LOAD_CONST               2 (('baz',))              8 BINARY_ADD             10 STORE_FAST               1 (tuple2)  4          12 LOAD_FAST                1 (tuple2)             14 RETURN_VALUE

The only difference is BUILD_TUPLE_UNPACK vs BINARY_ADD. The exact performance depends on the Python interpreter implementation, but it's natural to implement BUILD_TUPLE_UNPACK faster than BINARY_ADD because BINARY_ADD is a polymorphic operator, requiring additional type calculation and implicit conversion.