SimPy is a process-based discrete-event simulation language based on
standard Python and released under the GNU LGPL.

It provides the modeller with components of a simulation model. These
include processes, for active components like customers, messages, and
vehicles, and resources, for passive components that form limited
capacity congestion points like servers, checkout counters, and
tunnels. It also provides monitor variables to aid in gathering
statistics.

Homepage:
https://simpy.readthedocs.io/
