[cairo] since which version? cairo.Format

[buhtz at posteo.de]

> > > It was added with 1.13, see
> > > https://pycairo.readthedocs.io/en/latest/reference/enums.html#cairo.Format  
> >
> > Is this "cairo.version" (pycairo) or "cairo.cairo_version()" (C
> > cairo library)?  
> 
> pycairo.

So this would do the trick I think.

if cairo.version_info >= (1, 13, 0):
    _surface_format = cairo.Format.RGB24,
else:
    _surface_format = cairo.FORMAT_RGB24