Helper types

epydemic uses networkx to represent the underlying networks. networkx is extremely fleible in how it represents the nmodes of a network (graph): pretty much any object can be used, although in practice one often encounters either strings or integers. (The latter are especially common in network science, as the nodes don’t actually represent “real” objects and so don’t have meaningful names.)

epydemic also uses Python type annotations on methods and attributes to improve programming safety. Since using Any types extensively isn’t very intuitive, we provide three “helper” types for describing the structure of networks:

• Node, the type of nodes, aliased to Any

• Edge, the type of edges, represented as a tuple of two Node objects

• Element, a union of Node and Edge

You’ll find these types used for each event function, and in the examples. Since they’re type aliases you can always use the underlying Any types if you prefer, but future versions of epydemic may make these types stronger rather than simply being aliases.