On 10/07/2008, Kent Johnson <[EMAIL PROTECTED]> wrote:
> The actual formal syntax definitions for the two are slightly different:
> http://docs.python.org/ref/lists.html
> http://docs.python.org/ref/genexpr.html
>
> Presumably this means there is something that is syntactically allowed
> in one form and not the other, but I can't figure out what it might
> be.
Is the generator expression grammar right? How do I parse, e.g.,
'(x+1 for x in range(10))'? Seems like there's nothing there for
'range(10)'. Like it should replace 'or_test' with 'old_expression'.
At any rate, here is one difference:
>>> a = range(5)
>>> b = range(5, 10)
>>> [x for x in a, b]
[[0, 1, 2, 3, 4], [5, 6, 7, 8, 9]]
>>> (x for x in a, b)
File "<stdin>", line 1
(x for x in a, b)
^
SyntaxError: invalid syntax
(I'm not sure I've ever used a list comprehension like that)
--
John.
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