Date: Mon, 25 Apr 2005 08:51:17 -0500 From: Mike Meyer <[EMAIL PROTECTED]>
Which means that the real rule should be always use generator
expressions,
unless you *know* the expression will always fit in memory.
Which leads to the obvious question of why the exception.
<code>
l = [(1, 2), ('a', 'b'), (3, 2), (23, 32)] l
[(1, 2), ('a', 'b'), (3, 2), (23, 32)] </code> This screen dump of the object is quite useful to me.
<code>
r = reversed(l) r
<listreverseiterator object at 0x009D2B90> </code> This screen dump of the object is less useful to me.
From a pure programming point of view it's not a sufficient reason tokeep list comprehensions, especially as the interpreter shell could be massaged into giving more output, but right here right now it's a lot easier to read the former than the latter IMHO.
(That is assuming I'm right in assuming functions like "reversed" are generator expressions).
No, generator expressions are like list comprehensions, only they create generator objects.
(x*x for x in xrange(1000))
versus
[x*x for x in xrange(1000))
Of course, one can always get an explicit list by passing the generator object to list(). This also works for most iterables like the one you showed above.
list(x*x for x in xrange(1000))
-- Robert Kern [EMAIL PROTECTED]
"In the fields of hell where the grass grows high Are the graves of dreams allowed to die." -- Richard Harter
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