What does "::" mean?

Paul Villani paul.villani at verizon.net
Fri Jul 22 22:04:14 CEST 2005

I'm very new to Python, but....

I think it's really ':' and ':' side-by-side with no values, not a single 

In V2.3 and higher, slicing supports an optional third index which works as 
a step, e.g.,


fetches every other item in indexes 2-8.  The useage you cite is really 
defaulting the start and end indexes, and decrementing the step index.


"could ildg" <could.net at gmail.com> wrote in message 
news:mailman.1932.1121820680.10512.python-list at python.org...
I know that ":" can do slice works.
But I saw "::" today and it puzzled me much,
I can't find it in the python doc,
so I raise this question here.
The code is as below:
Jython 2.2a1 on java1.5.0_03 (JIT: null)
Type "copyright", "credits" or "license" for more information.
>>> live='live';print live
>>> live=live[::-1];print live
"[::-1]" can reverse a string magicly, how did it do it? 

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