In article <lu************ @lairds.us>,
cl****@lairds.u s (Cameron Laird)
wrote:
In article <ma************ *************** **********@pyth on.org>,
Matthew Fitzgibbons <el*****@nienna .orgwrote:
Alexnb wrote:
Okay this is a simple question I just don't know how. If I have a list,
say:
funList = []
and after a while something possible should have been appended to it, but
wasn't. How can I test if that list is empty.
if not funList:
do_something()
.
.
.
It's also perfectly legitimate--and arguably even more
precise--to write
if funList == []:
do_something()
Any of these will be true for an empty list and false for a non-empty list:
not funList
len(funList) == 0
funList == []
Where they differ is how they behave for values of funList which are not
lists. For example, if you did funList = (), then the first two would be
true and the last one false. If you did funList = 0, the first and last
would be true, and the middle one would raise an exception.
The point is that if you're *sure* the item in question is going to be a
list, then any of them are pretty much as good as any other. If it's a
parameter that's being passed into a routine, so you can't be sure what
type it is, then you should be thinking a little harder about how flexible
you want to be.
