nctoolkit: A Python package for netCDF analysis and post-processing

This is a major release with some improvements and new methods.

This release requires that CDO version 2.0.5 or above is installed. Code written for the previous version of nctoolkit will be compatible.

The cost of maintaining support for CDO versions 1.9.10 and below was increasingly high compared with the declining user base for these versions, so support has been dropped.

A method for inverting vertical levels and latitude will be introduced: invert.

The pub_plot method will use slightly better colour scales for diverging scales.

Some improvements have been made to package internals.