On 30 March 2017 at 10:51, Mark E. Haase <mehaase@gmail.com> wrote:
> Your example is really repeating two things:
>
> d = [ [0 for _ in range(5)] for _ in range(10) ]
>
> But since list() uses * for repetition, you could write it more concisely
> as:
>
> d = [[0] * 5] * 10]
>
> I'm not picking on your specific example. I am only pointing out that Python
> gives you the tools you need to build nice APIs. If repetition is an
> important part of something you're working on, then consider using
> itertools.repeat, writing your own domain-specific repeat() method, or even
> override * like list() does. One of the coolest aspects of Python is how a
> relatively small set of abstractions can be combined to create lots of
> useful behaviors.

I find it weird that not the author, neither the previous repliers noticed that
"a repetition other than a for with dummy variable" was already in plain sight,
in the very example given.
Of course one is also free to write [ [0 for _ in range(5)] for _ in
range(10)] if he wishes so.