J a écrit :
Ok... I know pretty much how .extend works on a list... basically it
just tacks the second list to the first list... like so:
lista=[1]
listb=[2,3]
lista.extend(listb)
print lista;
[1, 2, 3]
what I'm confused on is why this returns None:
So why the None? Is this because what's really happening is that
extend() and append() are directly manipulating the lista object and
thus not actuall returning a new object?
Exactly.
Even if that assumption of mine is correct, I would have expected
something like this to work:
lista=[1]
listb=[2,3]
print (lista.extend(listb))
None
So what ? It JustWork(tm). list.extend returns None, so "None" is
printed !-)
(snip)
So changing debugger.printout() to:
def printout(self,*info):
lets me pass in multiple lists... and I can do this:
for tlist in info:
for item in tlist:
print item
which works well...
So, what I'm curious about, is there a list comprehension or other
means to reduce that to a single line?
Why do you think the above code needs to be "reduced to a single line" ?
What's wrong with this snippet ???
It's more of a curiosity thing at this point... and not a huge
difference in code... I was just curious about how to make that work.
Uh, ok.
What about:
from itertools import chain
def printout(*infos):
print "\n".join("%s" % item for item in chain(*infos))
HTH
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