[python - SimplexTree] boundary of a simplex

[VincentRouvreau]

We have python interfaces for the inefficient access to coboundaries (get_cofaces), but we seem to be missing access to the more natural boundaries...

[mglisse]

itertools.combinations(s,len(s)-1)

[VincentRouvreau]

@mglisse now that #362 is merged, do we keep this issue to show how to get boundaries in pure python ?

[mglisse]

If you want we can add to the documentation of the new function a sentence like

If you do not need the filtration values, the boundary can also be obtained as itertools.combinations(s,len(s)-1)

but I don't think we need to keep this issue open.