Temporal Training Exercises - Python

A series of hands-on exercises to learn Temporal workflow development using Python.

Prerequisites

• Python 3.8+
• Temporal Server running locally (port 7233)
• UV package manager

Setup

1. Install dependencies:

   uv sync

2. Start Temporal Server (in separate terminal):

   temporal server start-dev --search-attribute AccountId=Text

Exercises

Exercise 1: Hello Temporal

Duration: 30 minutes
Focus: Basic workflow and activity concepts

• Implement your first Temporal workflow
• Create activities for external operations
• Set up workers and execute workflows

Exercise 2: Money Transfer with Signals

Duration: 45 minutes
Focus: Signals and human-in-the-loop processes

• Handle external signals in workflows
• Implement conditional logic based on signals
• Build approval-based business processes

Exercise 3: Money Transfer with Queries

Duration: 30 minutes
Focus: Workflow observability and state monitoring

• Add query methods to expose workflow state
• Track workflow progress in real-time
• Monitor workflow execution from external clients

Exercise 4: Money Transfer with Search Attributes

Duration: 15 minutes
Focus: Workflow discoverability and filtering

• Implement search attributes for workflow metadata
• Enable workflow filtering in Temporal Web UI
• Make workflows discoverable by business criteria

Exercise 5: User Metadata & Activity Summaries

Duration: 30 minutes
Focus: Workflow observability and metadata

• Add activity summaries for runtime context
• Improve workflow observability in Temporal Web UI
• Understand metadata best practices
• Enhance debugging capabilities

Exercise 6: Unit Testing

Duration: 45 minutes
Focus: Testing workflows, activities, signals, and queries

• Write comprehensive unit tests for Temporal workflows
• Test activity success and failure scenarios
• Verify signal handling and query responses
• Mock external dependencies for predictable tests

Exercise 7: Manual Activity Retry

Duration: 45 minutes
Focus: Manual retry patterns and signal-based error correction

• Implement manual retry patterns using signals
• Handle non-retryable activity failures
• Interactive error correction workflows
• Dynamic request updates during execution

Running Exercises

Each exercise follows the same pattern:

1. Start the worker:

   uv run exercise{N}/start_worker.py

2. Execute the workflow:

   uv run exercise{N}/start_workflow.py

For Exercise 6 (Unit Testing):

uv run exercise6/run_tests.py

Solutions

Complete solutions are available in the solution{N}/ directories for reference.

Solution 6: Unit Testing

Comprehensive unit tests for Temporal workflows and activities:

• Activity testing with mocked failures
• Workflow testing with different scenarios
• Query and signal testing
• State transition validation

Running Tests:

cd solution6
uv run python run_tests.py

Solution 7: Manual Activity Retry

Manual retry patterns for handling invalid data scenarios:

• Non-retryable activity failures with ApplicationError
• Signal-based retry mechanisms
• Interactive error correction workflows
• Dynamic request updates during execution

Key Concepts Covered

• Workflows: Orchestration logic and state management
• Activities: External operations and side effects
• Workers: Task execution and polling
• Signals: External events and workflow modification
• Queries: Real-time workflow state inspection
• Search Attributes: Workflow metadata and discoverability
• Error Handling: Retries and failure management
• Unit Testing: Testing workflows and activities with mocked dependencies
• Manual Activity Retry: Signal-based retry patterns and error correction