Possible Duplicate:
Explain slice notation
I'm trying to understand the following piece of code:
# node list
n = []
for i in xrange(1, numnodes + 1):
tmp = session.newobject();
n.append(tmp)
link(n[0], n[-1])
Specifically, I don't understand what the index -1
refers to. If the index 0
refers to the first element, then what does -1
refer to?
List indexes of -x mean the xth item from the end of the list, so n[-1]
means the last item in the list n
. Any good Python tutorial should have told you this.
It's an unusual convention that only a few other languages besides Python have adopted, but it is extraordinarily useful; in any other language you'll spend a lot of time writing n[n.length-1]
to access the last item of a list.
Source: Stackoverflow.com