Question about tuple lengths
Delaney, Timothy (Tim)
tdelaney at avaya.com
Wed Dec 14 18:00:16 EST 2005
Dave Hansen wrote:
>>>> t2 = (1,2) # 2 element tuple
>>>> t1 = (1,) # 1 element tuple
>>>> t0 = (,) # 0 element tuple?
> File "<stdin>", line 1
> t0 = (,)
> ^
> SyntaxError: invalid syntax
>>>> t0 = () # Guess not, try parens with no comma
>>>> print t0, t1, t2
> () (1,) (1, 2)
That's still just a case of disambiguating. A single comma creates a
single-element tuple. Therefore, zero commas create a zero-length tuple.
Unfortunately, there's no way to indicate the lack of a comma without
disambiguating via parentheses.
Now, if you've got *more* than 1 element, you can omit the final comma.
*This* is the inconsistency (and it's the same with lists, dictionaries,
function argument lists, etc).
Tim Delaney
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