making the _config_path configurable in __init__.py?

[v7nguyen]

Hi Brian,

I am attempting to deploy Herbie as part of a Lambda function in AWS. The issue is that Lambda functions can only write to a specific "/tmp" folder. This throws an error when init.py is run since it is trying to create a directory for the config file (Line 82). Do you know if there is a way to change or specify the config path?

[ERROR] OSError: [Errno 30] Read-only file system: '/home/sbx_user1051'
Traceback (most recent call last):
  File "/opt/conda-env/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/opt/my-code/herbie_script.py", line 1, in <module>
    import get_forecast
  File "/opt/my-code/get_forecast.py", line 4, in <module>
    from herbie.tools import fast_Herbie_xarray
  **File "/opt/conda-env/lib/python3.10/site-packages/herbie/__init__.py", line 82, in <module>
    _config_path.parent.mkdir(parents=True, exist_ok=True)**
  File "/opt/conda-env/lib/python3.10/pathlib.py", line 1179, in mkdir
    self.parent.mkdir(parents=True, exist_ok=True)
  File "/opt/conda-env/lib/python3.10/pathlib.py", line 1179, in mkdir
    self.parent.mkdir(parents=True, exist_ok=True)
  File "/opt/conda-env/lib/python3.10/pathlib.py", line 1175, in mkdir
    self._accessor.mkdir(self, mode)

[blaylockbk]

The config path (and data save path) is hard-coded to go in the users home directory.

Herbie/herbie/__init__.py

Lines 53 to 59 in 02acbd1

	_config_path = Path("~/.config/herbie/config.toml").expand()
	# NOTE: The `\\` is an escape character in TOML.
	# For Windows paths "C:\\user\\"" needs to be "C:\\\\user\\\\""
	_save_dir = str(Path("~/data").expand())
	_save_dir = _save_dir.replace("\\", "\\\\")

You could manually change that path in your copy of the code.

I suppose there could be a check to see if that default path exists, and if it doesn't then write the config file to the current location.