Kedro pipeline_registry.py
==========================

With the realease of came a new module in the project template . Here are some notes that I learned while playing with this new module.

Date: March 20, 2021

With the realease of `kedro==0.17.2` came a new module in the project template
`pipeline_registry.py`. Here are some notes that I learned while playing with
this new module.

## migrating to `pipeline_registry.py`

* create a `src//pipeline_registry.py` file create a
* `register_pipelines` function in `pipeline_registry.py` that mirrors the
* register_pipelines method from your `hooks.py` module do not bring the
* `hook_impl` decorator remove register_pipelines method on your `ProjectHooks`
* class

You should now have something that looks like this in your
`src//pipeline_registry.py`.

``` python
"""Project pipelines."""
from typing import Dict

from kedro.pipeline import Pipeline

def register_pipelines() -> Dict[str, Pipeline]:
 """Register the project's pipelines.

 Returns: A mapping from a pipeline name to a ``Pipeline`` object.
 """
 return {"__default__": Pipeline([])}
```

> pipeline_registry only works in `kedro>=0.17.2`

## Conflict Resolution

_What happens If I register pipelines in both places_

I was not able to find any official documentation on how conflict resolution
worked so I stepped into a project and added to both my `hooks.py` and
`pipeline_registry.py` file. I noticed that it would pick up pipelines from
both modules, but pipelines from `hooks.py` always take precedence. The entire
duplicate pipeline will be over written by the one from `hooks.py`.

> kedro automatically merges pipelines from both hooks.py takes precedence

## Ready to update

In my experience there were no issues upgrading from `0.17.1` to `0.17.2`. I
would reccomend only having one `register_pipelines` so decide to migrate to
the new `pipeline_registry.py` or keep it in your `hooks.py`, but both is only
going to lead to confusion.

https://twitter.com/datajoely/status/1375193511264456705