pytransitions/transitions
Transitions
Transitions is an object-oriented finite state machine library for Python. It provides a framework for managing valid states and the logic for moving between them, including implementations for asynchronous state machines and thread-safe state managers.
The library supports hierarchical state machines that allow states to be nested to organize complex subtasks and logical contexts. It includes tools for generating visual diagrams of states and transitions to document machine logic.
The project covers state management primitives such as lifecycle callbacks, conditional transition guarding, and state property tagging. It also provides capabilities for state persistence through serialization and automated transitions based on state timeouts.
Features
- Finite State Machine Engines - Provides an object-oriented finite state machine engine for managing states and transitions in Python.
- State Transition Lifecycle Hooks - Provides automatic callbacks triggered during the entry and exit phases of state transitions.
- Hierarchical State Composition - Supports hierarchical state nesting where sub-states inherit and override the logic of parent states.
- Asynchronous State Transitions - Implements an asynchronous state machine that manages concurrent events and transitions using task runners.
- State Lifecycle Callbacks - Executes registered functions automatically during specific transition phases like entry and exit.
- Hierarchical State Machines - Implements a system for nesting states within other states to organize complex subtasks and logical contexts.
- Object-Oriented State Mapping - Maps finite state machine logic directly onto Python objects by dynamically adding transition methods to their classes.
- State Transition Models - Defines the trigger, source, and destination required to move a model from one state to another.
- Conditional Transition Guards - Evaluates boolean conditions to determine if a transition between states is permitted.
- State-Transition Execution - Triggers state moves by calling attached methods on a model or using dynamic trigger mechanisms.
- Asynchronous State Transition Frameworks - Provides a framework for executing state changes that incorporate asynchronous operations and lifecycle hooks.
- State Transition Validation - Verifies if a transition is permissible from the current state by evaluating conditions without executing the move.
- Transition Event Queueing - Processes events sequentially in a queue to ensure one transition finishes before the next one begins.
- State Logic Visualizers - Generates visual diagrams of states and transitions to document the logic of the state machine.
- State Machine Visualizations - Provides tools for generating visual diagrams of states and transitions to document machine logic.
- Reentrant Locks - Uses reentrant locks to prevent race conditions during simultaneous state transition triggers.
- Asynchronous Event Loops - Implements non-blocking transitions and concurrent state changes using asynchronous event loop integration.
- Asynchronous Action Handling - Manages concurrent transitions and task runners to prevent conflicts in non-blocking applications.
- Persistence and Serialization - Provides utilities for serializing and persisting the current state of a machine across sessions.
- Machine State Serialization - Saves and loads the current status of a state machine to persist progress across sessions.
- Automated Transition Generators - Generates methods that allow a model to move to any target state regardless of its current position.
- Thread-Safe State Transitions - Prevents data corruption during event dispatching via reentrant locks to ensure atomic state updates.
- Dynamic Method Generation - Dynamically creates trigger methods on the fly to facilitate state transitions based on configuration.
- State Timeouts - Automatically triggers events after a state has remained active for a specified duration of time.
- Algorithms and Patterns - Lightweight finite state machine implementation.
