Bring your towel and join one of the fastest growing data communities. Welcome to our second-generation open source orchestration platform, a completely rethought approach to dataflow automation.

Prefect Community

<@ULVA73B9P> I've got this piece of code.
child_flow_5 always fails. How do I get the parent_flow to continue with the execution of the rest of the child flows?
```from prefect import flow, serve, allow_failure


@flow(log_prints=True, flow_run_name="child_flow_{flow_param}")
def child_flow(flow_param: int):
    print(f"In flow {flow_param}")
    if flow_param==5:
        raise ValueError("child_flow_5 always fails")


@flow(log_prints=True)
def parent_flow():
    for i in range(0,11):
        allow_failure


if __name__ == "__main__":
    parent_flow_deployment = parent_flow.to_deployment(name="parent_flow_dev_deployment")
    serve(parent_flow_deployment)```

To ensure that your `parent_flow` continues executing even if `child_flow_5` fails, you should use the `allow_failure` function correctly. The `allow_failure` decorator allows a task or flow to fail without failing the entire flow run.

Here's a corrected version of your code:

```python
from prefect import flow, serve, allow_failure

@flow(log_prints=True, flow_run_name="child_flow_{flow_param}")
def child_flow(flow_param: int):
    print(f"In flow {flow_param}")
    if flow_param == 5:
        raise ValueError("child_flow_5 always fails")

@flow(log_prints=True)
def parent_flow():
    for i in range(0, 11):
        allow_failure(child_flow)(flow_param=i)

if __name__ == "__main__":
    parent_flow_deployment = parent_flow.to_deployment(name="parent_flow_dev_deployment")
    serve(parent_flow_deployment)
```

### Key Changes:
- *Use `allow_failure`*: Wrap the `child_flow` call with `allow_failure` to let it fail without stopping the `parent_flow`.
  
### Resources:
- <https://docs.prefect.io/api-ref/prefect/|Prefect 3.x API Reference>
- <https://docs-3.prefect.io/|Prefect 3.x Documentation>

This should allow your `parent_flow` to continue executing all child flows, even if `child_flow_5` raises an exception. If you have any more questions or need further assistance, feel free to ask.

<@ULVA73B9P> No the code that you provided is incorrect.
`'allow_failure' object is not callable`

It seems I made an error in my previous response regarding the use of `allow_failure`. Let's correct that.

To allow a child flow to fail without stopping the parent flow, you can use the `try-except` block directly within your flow. Here's how you can modify your `parent_flow` to handle failures in `child_flow_5`:

```python
from prefect import flow, serve

@flow(log_prints=True, flow_run_name="child_flow_{flow_param}")
def child_flow(flow_param: int):
    print(f"In flow {flow_param}")
    if flow_param == 5:
        raise ValueError("child_flow_5 always fails")

@flow(log_prints=True)
def parent_flow():
    for i in range(0, 11):
        try:
            child_flow(flow_param=i)
        except Exception as e:
            print(f"Child flow {i} failed with exception: {e}")

if __name__ == "__main__":
    parent_flow_deployment = parent_flow.to_deployment(name="parent_flow_dev_deployment")
    serve(parent_flow_deployment)
```

### Key Changes:
- *Wrap `child_flow` call in a `try-except` block*: This allows each child flow to fail independently without affecting the rest of the flow execution.

This approach should allow your `parent_flow` to continue executing all child flows, even if one of them raises an exception. If you have further questions, feel free to ask.