Hi Νίκος, On 2010-08-19 09:10, Νίκος wrote: > On 18 Αύγ, 12:50, Cameron Simpson <c...@zip.com.au> wrote: >> >> ("nikos",) is a single element tuple. >> ["nikos"] is a single element list. >> ["nikos",] is also a single element list, just written like the tuple. > > It makes more sense if i: > > "nikos" is just a string > ("nikos") is a single element tuple > ["nikos"] is also a single element list > > After all () used to define tuples and [] usedd to define lists. Why > commas?
Because parentheses are also used to group expressions. For example, >>> 2 * (1+2) 6 If it were as you would like, the result would have been (3, 3) So because <something_without_commas> inside parentheses already denotes an expression you have to add a comma to distinguish a one-element tuple from an expression. Stefan -- http://mail.python.org/mailman/listinfo/python-list