Python Hints

Dropping support for Python 2.7

As of Clawpack v5.7.0 we are no longer supporting Python 2.7, and Python 3.x is expected, see v5.7.0 release notes. At this point we believe v5.7.0 still works with Python 2.7, but we are phasing out testing this in the future.

This is consistent with the fact that Python 2.7 itself will not be maintained beyond January, 2020, and most package we rely on (e.g. numpy, matplotlib, jupyter) are also ceasing support for Python 2.7, see

Hence we view Clawpack version 5.6.x as the end of the line for Python 2 support (probably 5.6.1 unless there’s a strong need to update this further). Clawpack 5.6.x will continue to be available, of course, but in order to take advantage of future improvements to Clawpack (and most other Python packages) we strongly suggest that you start converting all of your codes to work in Python 3 if you haven’t already. Often this only requires changing print statements to print functions, but there are a few other changes. See e.g., and other online resources discussing the differences between Python 2 and 3.

References and tutorials

For use with Clawpack, you will need the Numpy module (Numerical Python) that allows working with arrays in much the same way as in Matlab. This is distributed as part of SciPy (Scientific Python). See the Installing SciPy page for tips installing SciPy and NumPy on various platforms.

For plotting you will also need the matplotlib module which provides Matlab-like plotting commands for 1d and 2d plots (e.g. contour and pcolor plots).

Some useful links to get started learning Python:


The Clawpack Gallery of Jupyter Notebooks contains a number of notebooks with other examples of using Python for Clawpack.