fix: Fix issue with dataframe scenario indexing

[jetuk]

Correction the look-up of dataframe data when using user combinations of scenarios.

Fixes #1110.

[knoxsp]

I tried to re-run the test model i posted in the issue, and have had the following error:

AttributeError: 'pywr.parameters._parameters.DataFrameParameter' object has no attribute '_Parameter__values'

This error had also been occurring on all my models from version 1.22, and on master. I've had to revert to v1.21 to fix this issue.

[jetuk]

Are you building with Cython 3?

[knoxsp]

>>> import cython
>>> cython.__version__
'0.29.36'

[knoxsp]

I can confirm that my larger model runs with this fix (applied to v1.21). I have not checked whether the correct scenario data is being used. Will report back.

[knoxsp]

Confirmed that the correct scenario data is being used. Checked manually with print statements in the value function of the DataFrameParamter class.

[jetuk]

Do you need this back-porting to 1.21 as well?

[knoxsp]

Do you need this back-porting to 1.21 as well?

I have upgraded cython to the latest version (3.0.4) and re-run using this branch. It now works as expected. So 1.22 doesn't work with pre-cython 3.

I can use cython 3 so i don't need this porting back to 1.21.