Python Design Patterns
The following chapters discuss each of the 23 design patterns featured in the Design Patterns book, along with at least one working program example for that pattern. The programs have some sort of visual interface as well to make them more immediate to you.
Which design patterns are most useful? This depends on the individual programmer. The ones we use the most are Command, Factory, Decorator, Façade, and Mediator, but we have used nearly every one at some point.