You might need to use a Python package that is not installed in the environment that runs your Code block and Decision nodes. For instance you might need nltk. BaseTen allows you to provide these dependencies through the UI. Open the settings menu, click on "Python environment", and enter your dependencies in the same way you would in a requirements.txt file.
🎡 Installing a custom Python wheel
And at times you might want to reuse some code that you've already written and would rather not have to copy/paste into BaseTen. You can instead package it up as a Python wheel and link to it in your requirements.