he expressions are
evaluated from left to right.

An asterisk "*" denotes *iterable unpacking*.  Its operand must be an
*iterable*.  The iterable is expanded into a sequence of items, which
are included in the new tuple, list, or set, at the site of the
unpacking.

New in version 3.5: Iterable unpacking in expression lists, originally
proposed by **PEP 448**.

The trailing comma is required only to create a single tuple (a.k.a. a
*singleton*); it is optional in all other cases.  A single expression
without a trailing comma doesn’t create a tuple, but rather yields the
value of that expression. (To create an empty tuple, use an empty pair
of parentheses: "()".)
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