2D List comprehension & replace

[Larry Bates]

I should not have given up so soon.

[[y or None for y in x] for x in l]

seems to do the trick.

-Larry Bates


"Larry Bates" <lbates at swamisoft.com> wrote in message
news:YuSdndB1QM85nczd4p2dnA at comcast.com...
> I've gone brain-dead trying to get this to work
> using list comprehensions.  I have a list of lists
> like the following:
>
> l=[[92.6, 0, 93.5],
>    [94.7, 95.6, 95.7],
>    [91.2, 92.1, 93.0]]
>
> what I want is a new list
> with the zero (0) replaced with None.
>
> I thought I would use the fact that the command:
>
> 0 or None
>
> seems to return None.
>
> This procedural code does the trick, but I just
> know it can be done with a single list comprehension.
>
> tol=[]
> for a in l:
>     til=[]
>     for v in a:
>         if a != 0: til.append(v)
>         else:      til.append(None)
>
>     tol.append(til)
>
> l=tol
>
> Thanks in advance.
>
> Larry Bates
>
>