Standarizing the way Switch writes output.

[bmaluenda]

• Removed the save_results and _save_results functions for exclusive use of the post_solve function. Replaced the latter in all modules which were still using save_results. This eliminates several redundancies.
• Since most new Switch users are also new Pyomo users, there is a very slim chance that they will be using old Pyomo versions, so I didn't import some snippet of code from save_results into post_solve which was supporting them. Since there were no checks for solver termination conditions and only a print statement, I put a generic printing of the condition on the solve module, if verbose option is on.
• Added an option for sorted output of generic variables. The capacity was already written, but no command line option was available.

Passes the tests and gives me the same output as in the examples folders. Code should be compatible with Hawaii modules, since its own save_results module has a post_solve function which will be called upon solver termination.

[josiahjohnston]

Great start! A few comments:

• When you do refactoring like this, you need to do a recursive multi-file search for your keyword. You missed save_results in several modules..

siah-laptop:switch josiah$ grep -rI save_results .
./.git/logs/HEAD:df2e1a90527e2869c6efbf329b4f72bec783482e 72493b1a2ca1c47528768ba04688b514951eeb27 josiah.johnston <josiah.johnston@gmail.com> 1471405430 -0700 rebase: added basic hawaii.save_results module
./examples/custom_extension/sunk_costs.py:save_results(model, instance, outdir)
./switch_mod/export/dump.py:def save_results(model, instance, outdir):
./switch_mod/export/example_export.py:def save_results(model, instance, outdir):
./switch_mod/utilities.py:    min_data_check(), load_inputs(), save_results().
./switch_mod/utilities.py:    # replace the old _save_results function

The first entry from the .git directory can obviously be ignored, but the next five hits should get fixed.

• The "ideal" way of posting changes is to restrict changes to just one feature per commit. Adding the option for sorting the output of the generic dump is a bit off-topic. I've broken that rule a bunch of times myself, but I try to stick to it these days because it makes the code history way easier to read through.
• Regarding that feature, you shouldn't stick that command line option into switch_mod/solve.py and use it in utilities.py. If you use a different entry point than switch_mod/solve.py and try to call instance.post_solve(), it generates an error because that option hasn't been defined. Really, the file that uses a command-line option should be the one defining it. A fairly clean way of dealing with that is to move _save_generic_results() and _save_total_cost_value() into switch_mod/export/init.py, add a post_solve() function that calls those two functions, add the command line option to that file, make switch_mod.export a core module listed in switch_mod/init.py, then finally remove references to _save_generic_results() and _save_total_cost_value() in utilities.post_solve().

Cheers, Josiah

[josiahjohnston]

I wrote that in a hurry last night, and neglected to summarize my comments into a punch-list. My proposed punch-list (should be quick & easy)

• Do a recursive search on the entire codebase and remove the remaining references to save_results.
• Remove the sort output command line option from this pull request.
  • Post that as a separate feature, implemented in a different way (either following the export module suggestion, or by moving the command-line option from solve.py into utilities.py

Thanks again for taking on this task of cleaning up the codebase! :)

[bmaluenda]

I think that your suggestion is great, so I moved the functions to the init.py file of the export module. Also, cleaned up remaining references and fixed some docstrings and imports. Finally, removed the deterministic output ordering option proposal. It is true that it corresponds to a different topic and should be pushed through another branch.

[josiahjohnston]

I'd suggest taking out the comment in utilities:

 # replace the old _save_results function

Other than that, looks good to me. 👍

[bmaluenda]

Thanks for the comments, merging now!