[Tutor] Counting the # of iterations OR storing # values in a list

[Peter Otten]

Gautam Desai wrote:

> I am currently working with the lattice.py code attached. The code is a
> simulation that models the interactions between bacteria by producing a
> lattice output.
> 
> Once you run the code, there should be both blue and red bacteria that
> show
> on a lattice.  I can manipulate the size of the lattice to be an integer.
> In this case, I have set it to 250
> 
> However, there are different bacteria cells occupying each "pixel" on the
> lattice. I could count the number of red or blue bacteria on the output,
> but It would take an extremely long time

Counting doesn't take very long, at least for *only* 250**2 cells, and 
there's even a Counter in the stdlib. When I tried

$ python3 -i lattice.py 
>>> from collections import Counter
>>> Counter(np.ravel(my_lattice.lattice))
Counter({0.22950000000000001: 31306, 0.0025400000000000002: 31194})

there was no noticeable delay on my aging hardware. For really large arrays

>>> (my_lattice.lattice == 0.2295).sum()
31306

is probably faster.