setup path with default and read from environment

[matbesancon]

specifically in HVAC2.py

############################################################################
# Setup

DATA_PATH = "PATH_TO_PYDR_DATA"
LOG_PATH = "PATH_TO_LOGS"
RESULTS_PATH = "PATH_TO_RESULTS"

This could be replaced by

import os
DATA_PATH = os.environ["DATA_PATH"]
LOG_PATH = os.environ["LOG_PATH"]
RESULTS_PATH = os.environ["RESULTS_PATH"]

If the folders are usually located to some given place relative to the current folder:

import pathlib
root_path = pathlib.Path().absolute().joinpath("..")
# DATA_PATH = .. something relative to root_path

[Balandat]

Sure, you can do that. I think there is enough manual setup involved that we don't really need to make this part particularly general / user-friendly, but happy to accept a PR

[matbesancon]

yes got it, it was mostly from a code discoverability perspective (being able to plug a local mode easily for some tests)