clean up open() functions to use self.auto() which does compression for us based on the file extension

update _const_dt to include a wrapper just before it's cached, allowing output to the screen for debugging

other minor fixes

few other cleanups

add automatic cacheing of various functions, and a cache_test() routine to test the runtimes with and without caching

set up json functions to not convert ascii (should be faster and preserve UTF8)

I've added a new grid_option, num_processes, which is the number of processes launched by Python's multiprocessing. num_cores is used to set this:

if > 0 use the number specified (as previously, so backwards compatibility is fine)
if == 0 use the number of logical cores
if == -1 use the number of physical cores

Try running it with a command like:

---
rm -rf /tmp/slurm ; nice python3.9 ./src/python/ensemble.py dists=Moe binaries=False r=100 verbosity=1 max_evolution_time=10 slurm_dir=/tmp/slurm slurm_partition=debug slurm_memory=100MB monte_carlo_kicks=0 save_ensemble_chunks=False num_cores=-1 slurm=1 slurm_njobs=2 num_cores=2
---

You will want to change num_cores and slurm_njobs to suit. Each Slurm job gets num_processes cores allocated to it.

Note: you should set your slurm directory to be empty. This isn't really required, but makes debugging a lot easier.

You also have to set the slurm_partition by hand - this is something you need to find out based on your cluster. In the above example I use "debug" because this is the default.

There are quite a few changes internally, particularly new functions to load, save and merge Population objects and their data (mostly) correctly, and updates to the dict merging functions that this required.

please report bugs because there will be many!

add a fix to distinguish between centred and edge grids when computing number of points over which we should loop and phasevols

also added a warning in the const_dt spacing function to catch the edge case where tmax or max_evolution_time are shorter than the first timestep, which would lead to an empty interpolation table

remove deprecated resolution setting

cleaned up some of the verbosity to be more like binary_grid and less annoying

updated the internal API for how grids are constructed to simplify the code

add option such that when resolution==0, the resolution is calculated automatically from the sample list.

add delete_grid_variable function

In my CEMP simulations, I use the above with something like this to zoom in around 0.8Msun in M1:

emp_population.update_grid_variable(
    name="lnm1",
    spacingfunc="gaussian_zoom(np.log(0.4),np.log(6.0),np.log(0.8),0.05,0.99,100)",
    resolution=0
)

Processed alot of what pylint suggested. Might change the naming conventions rules tho, the short parameter names are an issue, but lets not get too strict..