I use kedro catalog create to boost my productivity by automatically generating yaml catalog entries for me. It will create new yaml files for each pipeline, fill in missiing catalog entries, and respect already existing
catalog entries. It will reformat the file, and sort it based on catalog key.

🤷‍♀️ What is Kedro (The Parts)

Waylon Walker ・ Feb 24 '20

#data #dataengineering #kedro #datascience

👆 Unsure what kedro is? Check out this post.

Running Kedro Catalog Create

The command to ensure there are catalog entries for every dataset in the passed in pipeline.

kedro catalog create --pipeline history_nodes

• Create's new yaml file, if needed
• Fills in new dataset entries with the default dataset
• Keeps existing datasets untouched
• it will reformat your yaml file a bit
  • default sorting will be applied
  • empty newlines will be removed

CONF_ROOT

Kedro will respect your CONF_ROOT settings when it creates a new catalog file, or looks for existing catalog files. You can change the location of your configuration files by editing your CONF_ROOT variable in your projects.

settings.py.

# settings.py
# default settings
CONF_ROOT = "conf"

# I like to package my configuration
CONF_ROOT = str(Path(__file__).parent / "conf")

I prefer to keep my configuration packaged inside of my project. This is partly due to how my team operates and deploys pipelines.

File Location

The kedro catalog create command will look for a yaml file based on the name of the pipeline (CONF_ROOT/catalog/<pipeline-name>.yml). If it does not
find one it will create one and make entries for each dataset in the pipeline. It will not look in all of your existing catalog files for entries, only the one in the exact file for your pipeline. If you are going to use this command
its important that you follow this pattern or copy what it generates into your own catalog file of choice.

⚠️ It will not look in all of your existing catalog files for entries, only the one in the exact file for your pipeline.

MemoryDataSet's

When you run kedro catalog create you get MemoryDataSet, that's it. As of 0.17.4 its hard coded into the library and not configurable.

range12:
  type: MemoryDataSet

Your free to use what you want though

Let's switch this dataset over to a pandas.CSVDataSet so that the file gets stored and we can pick up and read the file without re-running the whole pipeline.

range12:
  type: pandas.CSVDataSet
  filepath: data/range12.csv

Continue adding nodes

As we work we will keep adding nodes to our kedro pipeline, in this case we added another node that created a dataset called range13.

kedro catalog create --pipeline history_nodes

After telling kedro to create new catalog entries for us we will see that it left our range12 entry alone and created range13 for us.

range12:
  type: pandas.CSVDataSet
  filepath: data/range12.csv
range13:
  type: MemoryDataSet

Formatting is not worthwhile

If we decide this is too cramped for us we could add some space between datasets. The next time we run kedro catalog create empty lines will be
removed.

range12:
  type: pandas.CSVDataSet

range13:
  type: MemoryDataSet

Continuing to work

If we coninue adding new nodes, and tell kedro to create catalog entries again, all of our effort given to formatting will be lost. I wouldn't worry about it unless you have an autoformatter that you can run on your yaml files. The productivity gains in an semi-automated catalog are worth it.

range12:
  type: pandas.CSVDataSet
  filepath: data/range12.csv
range121:
  type: MemoryDataSet
range13:
  type: MemoryDataSet

Sorting Order

Notice the sorting order in the last entry, range121 comes before range13. This is all based on how pythons yaml.safe_dump works, kedro has set the default_flow_style to False. You can see where they write your file in the source code currently here