On 12/12/2011 8:19 AM, Antoine Pitrou wrote:
Le lundi 12 décembre 2011 à 08:15 -0500, Ned Batchelder a écrit :
Believe me, I understand the issues. It is true, though that the single-element tuple syntax is often a surprise to people, and often well into their Python learning experience. We often repeat, "it isn't parens that make a tuple, but a comma." Then why when displaying a tuple does Python insist on using parens around it?
1, 2, 3
(1, 2, 3)
I would say:
- because it's easier to read (subjectively so, I guess)
- because it's easier to copy/paste into an expression without running
into precedence problems
Yes, those are good reasons. And you can see why Python's insistence on showing tuples with parens contributes to the gotcha that the parens are a red herring, and it's the commas that are important. Also, who hasn't said this to a beginner: "lists and tuples are very similar, lists use square brackets, tuples use parens"? Somehow, in a list, the commas don't make a tuple... It's complicated.
I welcome Richard's help in explaining this issue to beginners.
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