[WIP] Add prefect manager support

examples/prefect_example.py

@@ -0,0 +1,207 @@
+"""
+Example demonstrating how to use jobflow with Prefect.
+
+This example shows how to:
+1. Create jobflow Jobs and Flows
+2. Convert them to Prefect workflows
+3. Run them locally using Prefect
+4. Create deployments for a Prefect cluster
+"""
+
+import jobflow
+from jobflow import job, Job, Flow
+from jobflow.managers.prefect import PrefectManager, run_on_prefect, flow_to_prefect_flow
+
+
+# Define some simple jobs
+@job
+def add(a: int, b: int) -> int:
+    """Add two numbers."""
+    print(f"Adding {a} + {b}")
+    return a + b
+
+
+@job
+def multiply(a: int, b: int) -> int:
+    """Multiply two numbers."""
+    print(f"Multiplying {a} * {b}")
+    return a * b
+
+
+@job
+def subtract(a: int, b: int) -> int:
+    """Subtract two numbers."""
+    print(f"Subtracting {a} - {b}")
+    return a - b
+
+
+def example_single_job():
+    """Example of running a single job with Prefect."""
+    print("\n=== Single Job Example ===")
+
+    # Create a simple job
+    job1 = add(5, 3)
+
+    try:
+        # Run using Prefect
+        result = run_on_prefect(job1, flow_name="single_add_job")
+        print(f"Result: {result}")
+    except ImportError:
+        print("Prefect is not installed. Please install with: pip install prefect")
+    except Exception as e:
+        print(f"Error running job: {e}")
+
+
+def example_simple_flow():
+    """Example of running a simple flow with Prefect."""
+    print("\n=== Simple Flow Example ===")
+
+    # Create jobs
+    job1 = add(5, 3)
+    job2 = multiply(job1.output, 2)
+    job3 = subtract(job2.output, 1)
+
+    # Create flow
+    flow = Flow([job1, job2, job3], output=job3.output, name="arithmetic_flow")
+
+    try:
+        # Run using Prefect
+        result = run_on_prefect(flow, flow_name="arithmetic_workflow")
+        print(f"Flow result: {result}")
+    except ImportError:
+        print("Prefect is not installed. Please install with: pip install prefect")
+    except Exception as e:
+        print(f"Error running flow: {e}")
+
+
+def example_parallel_flow():
+    """Example of running a parallel flow with Prefect."""
+    print("\n=== Parallel Flow Example ===")
+
+    # Create independent jobs that can run in parallel
+    job1 = add(1, 2)
+    job2 = add(3, 4)
+    job3 = add(5, 6)
+
+    # These jobs depend on the parallel jobs
+    job4 = multiply(job1.output, job2.output)
+    job5 = multiply(job3.output, 2)
+
+    # Final job combines everything
+    job6 = add(job4.output, job5.output)
+
+    # Create flow
+    flow = Flow(
+        [job1, job2, job3, job4, job5, job6], 
+        output=job6.output, 
+        name="parallel_arithmetic_flow"
+    )
+
+    try:
+        # Run using Prefect with concurrent task runner
+        result = run_on_prefect(
+            flow, 
+            flow_name="parallel_workflow",
+            task_runner="concurrent"
+        )
+        print(f"Parallel flow result: {result}")
+    except ImportError:
+        print("Prefect is not installed. Please install with: pip install prefect")
+    except Exception as e:
+        print(f"Error running parallel flow: {e}")
+
+
+def example_prefect_manager():
+    """Example using the PrefectManager class."""
+    print("\n=== PrefectManager Example ===")
+
+    try:
+        # Create manager
+        manager = PrefectManager(task_runner="sequential")
+
+        # Create a flow
+        job1 = add(10, 5)
+        job2 = multiply(job1.output, 3)
+        flow = Flow([job1, job2], output=job2.output, name="manager_test_flow")
+
+        # Submit flow (this would be async in real usage)
+        print("Creating Prefect flow...")
+        prefect_flow = flow_to_prefect_flow(flow, flow_name="manager_workflow")
+        print(f"Created Prefect flow: {prefect_flow}")
+
+        # You could also create a deployment like this:
+        # deployment = manager.create_deployment(
+        #     flow,
+        #     deployment_name="my_deployment",
+        #     work_pool_name="my_work_pool"
+        # )
+        # print(f"Created deployment: {deployment}")
+
+    except ImportError:
+        print("Prefect is not installed. Please install with: pip install prefect")
+    except Exception as e:
+        print(f"Error with PrefectManager: {e}")
+
+
+def example_error_handling():
+    """Example showing error handling in Prefect workflows."""
+    print("\n=== Error Handling Example ===")
+
+    @job
+    def divide(a: int, b: int) -> float:
+        """Divide two numbers."""
+        if b == 0:
+            raise ValueError("Cannot divide by zero!")
+        return a / b
+
+    # First, show a successful division
+    working_job = divide(10, 2)
+    try:
+        result = run_on_prefect(working_job, flow_name="working_division")
+        print(f"Successful division result: {list(result.values())[0]}")
+    except Exception as e:
+        print(f"Error in working job: {e}")
+        return
+
+    # Now show error handling (this will generate Prefect error logs, but that's expected)
+    print("Testing error handling (expect to see error logs below)...")
+    failing_job = divide(10, 0)
+
+    try:
+        result = run_on_prefect(failing_job, flow_name="failing_job")
+        print(f"❌ Unexpected success: {result}")
+    except ImportError:
+        print("Prefect is not installed. Please install with: pip install prefect")
+    except Exception as e:
+        print(f"✅ Expected error caught and handled: {type(e).__name__}: {e}")
+        print("   (The error traceback above is expected - Prefect logs all failures)")
+
+
+if __name__ == "__main__":
+    print("Jobflow + Prefect Integration Examples")
+    print("=====================================")
+    print("NOTE: Error tracebacks in logs are expected for the error handling example.")
+    print("      The examples demonstrate both successful execution and error handling.")
+    print()
+
+    # Check if Prefect is available
+    try:
+        import prefect
+        print(f"Prefect version: {prefect.__version__}")
+    except ImportError:
+        print("Prefect is not installed. Some examples will not work.")
+        print("Install with: pip install prefect")
+
+    # Run examples
+    example_single_job()
+    example_simple_flow()
+    example_parallel_flow()
+    example_prefect_manager()
+    example_error_handling()
+
+    print("\n=== Examples Complete ===")
+    print("To deploy to a Prefect cluster:")
+    print("1. Start Prefect server: prefect server start")
+    print("2. Create work pool: prefect work-pool create --type process my_pool")
+    print("3. Create deployment using PrefectManager.create_deployment()")
+    print("4. Run worker: prefect worker start --pool my_pool")

pyproject.toml

@@ -25,7 +25,7 @@ classifiers = [
     "Topic :: Other/Nonlisted Topic",
     "Topic :: Scientific/Engineering",
 ]
-requires-python = ">=3.10"
+requires-python = ">=3.11"
 dependencies = [
     "PyYAML",
     "maggma>=0.57.0",
@@ -34,6 +34,8 @@ dependencies = [
     "pydantic-settings>=2.0.3",
     "pydantic>=2.0.1",
     "pydash",
+    "prefect",
+    "pytest",
 ]
 
 [project.optional-dependencies]
@@ -51,6 +53,7 @@ dev = ["pre-commit>=2.12.1", "typing_extensions; python_version < '3.11'"]
 tests = ["moto==5.1.9", "pytest-cov==6.2.1", "pytest==8.4.1"]
 vis = ["matplotlib", "pydot"]
 fireworks = ["FireWorks"]
+prefect = ["prefect>=3.0.0"]
 strict = [
     "FireWorks==2.0.4",
     "PyYAML==6.0.2",

src/jobflow/__init__.py

@@ -8,6 +8,12 @@
 from jobflow.core.state import CURRENT_JOB
 from jobflow.core.store import JobStore
 from jobflow.managers.local import run_locally
+
+try:
+    from jobflow.managers.prefect import PrefectManager, run_on_prefect
+except ImportError:
+    PrefectManager = None
+    run_on_prefect = None
 from jobflow.settings import JobflowSettings
 from jobflow.utils.log import initialize_logger