Python newbies often have some confusion about how to make one-element tuples.  VenkataSubramanian provided a nice summary of Python's tuple syntax [[#1|[1]]].

=== Zero Element Tuples ===

In Python, zero-element tuples look like:{{{
()
}}}
In this form, unlike the other tuple forms, parentheses are the essential elements, not commas.

=== One Element Tuples ===

One-element tuples look like:{{{
1,
}}}
The essential element here is the trailing comma.  As for any expression, parentheses are optional, so you may also write one-element tuples like {{{
(1,)
}}}
but it is the comma, not the parentheses, that define the tuple.

=== Multiple Element Tuples ===

In Python, multiple-element tuples look like:{{{
1,2,3
}}}
The essential elements are the commas between each element of the tuple.  Multiple-element tuples may be written with a trailing comma, e.g. {{{
1,2,3,
}}}
but the trailing comma is completely optional.  Just like all other expressions in Python, multiple-element tuples may be enclosed in parentheses, e.g. {{{
(1,2,3)
or
(1,2,3,)
}}}
but again, it is the commas, not the parentheses, that define the tuple.

<<Anchor(1)>> [1] http://mail.python.org/pipermail/python-list/2005-June/284208.html