Search the difference: Why this function defenition does'nt work?
LLoeffler at home.com
Sat Dec 22 18:54:37 CET 2001
If you use a list index  that returns a single element of the type
that that element is (which is what you want in this case). But when
you use the colon for slice notation, you are asking python to return a
tuple of all the elements up to the zeroth element, which is no
elements--an empty tuple. Then you are trying to add a number to a
tuple which is undefined.
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