Yes, I have heard of both Pelican and Lektor, I see that they both have plugin systems that allow you to hook in custom Python code via signals / events, should

Yes, I have heard of both Pelican and Lektor, I see that they both have plugin systems that allow you to hook in custom Python code via signals / events, should give them a try too (especially Lektor, which is newer, and which I know was written by the author of Flask et al).