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Versatile and flexible Python State Machine library.

It can do simple things like this:

Or somewhat more complex like that:

The State Patternsolves many problems, untangles the code and saves one's sanity.Yet.., it's a bit rigid and doesn't scale. The goal of this library is to giveyou a close to the State Pattern simplicity with much more flexibility. And,if needed, the full state machine functionality, includingFSM,HSM,PDA and other tasty things.

• Provide a State Pattern-like behavior with more flexibility (seeDocumentation forexamples)
• Be explicit and don't add any magic code to objects that use pysm
• Handle directly any kind of event or input (not only strings) - parsingstrings is cool again!
• Keep it simple, even for someone who's not very familiar with the FSMterminology

• Finite State Machine (FSM)
• Hierarchical State Machine (HSM) with Internal/External/Local transitions
• Pushdown Automaton (PDA)
• Transition callbacks - action, before, after
• State hooks - enter, exit, and other event handlers
• Entry and exit actions are associated with states, not transitions
• Events may be anything as long as they're hashable
• States history and transition to previous states
• Conditional transitions (if/elif/else-like logic)
• Explicit behaviour (no method or attribute is added to the object containing a state machine)
• No need to extend a class with State Machine class (composition over inheritance)
• Fast (even with hundreds of transition rules)
• Not too many pythonisms, so that it's easily portable to other languages (ie.JavaScript).
• Micropython support

Install pysm fromPyPI:

pip install pysm

or clone theGithub pysm repository:

git clone https://github.com/pgularski/pysmcd pysmpython setup.py install

Read the docs for API documentation and examples -http://pysm.readthedocs.io/

See Unit Tests to see it working and extensively tested.

The library works with pyboards!:

import upipupip.install('upysm')

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• Examples