Avoid in-place multiplication of color list

[eldond]

• Was ensuring enough colors for overlays by colors *= nc
• This updates the source color list; repeated calls with the same colors object were resulting in the list of colors elongating until a MemoryError was triggered

[smithsp]

Maybe https://matplotlib.org/cycler/ would be helpful here?

[eldond]

@smithsp it doesn't seem easy to use cycler this time. I want definite colors for each value of a counter, and I may use two loops over the same thing in places.

[codecov[bot]]

Codecov Report

Merging #133 into master will decrease coverage by 0.00%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #133      +/-   ##
==========================================
- Coverage   79.80%   79.80%   -0.01%     
==========================================
  Files          50       50              
  Lines        9562     9561       -1     
==========================================
- Hits         7631     7630       -1     
  Misses       1931     1931              

Impacted Files	Coverage Δ
omas/omas_plot.py	78.76% <100.00%> (-0.02%)	:arrow_down:

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[smithsp]

@eldond Maybe the matplotlib cycler was too much. I investigated further and it uses itertools.cycle underneath, which could be used as:

for i,(l,c) in enumerate(zip(labels,itertools.cycle(colors))):

or

colors = [c for c in zip(labels, itertools.cycle(color))]
...
   colors[i]

[eldond]

@smithsp I don't know how to test for how the plots look in terms of using consistent or reasonable colors, so the unit tests won't catch a problem with the wrong coloration due to a mishap with a cycler. So, that increases the time and effort required for redevelopment and testing and I can't do it right now. You're welcome to take over or open an issue if you think it's important. I agree that using a cycler from the start would've been nicer than these lists, and I'll try to remember to do that next time.

[smithsp]

@eldond I'm not going to take over. I just wanted to make sure that you were aware when you have the bandwidth.