[cairo] Pycairo + PNG Output

[Ccx]

Hello, I'm going to use Pycairo for generating graphics on webserver.

As far as I found out, Pycairo can be set to draw either to memory in a
raw data or to a png file, but not to a memory in png format which I need.

So I ask, is there way to do it with pycairo as it is or will it need
some reimplementation.
I can try to help in the second case, I have some experience with C, C++
and Python, but not with extending Python (I've just read the guide).

Thanks
    Jan Pobrislo