Examples for Python script in knime

[JJV]

Hello everyone, I’m trying to learn how to apply Python script in knime, but I’m not really understanding the logic of how it works, I already integrated Anaconda and prepared the extensions in my WF. Now, I don’t understand how, for example, to use data from a table and modify it using the python script node.
Does anyone have an example to learn the mechanics of use?
Thanks a lot

[mlauber71]

@JJV you can use the KNIME Python integration then you will not have to worry about Conda and so on.

How to set up Python extensions in KNIME | KNIME

Here you have a most basic Python in an out example:

Python scripting node data input

@Bob_Nisbet the in and out syntax would look like this for pandas dataframes. import knime.scripting.io as knio import numpy as np import pandas as pd # data from KNIME to Python (pandas) df = knio.input_tables[0].to_pandas() # data from python (pandas) to KNIME knio.output_tables[0] = knio.Table.from_pandas(df) KNIME would work internally with Arrow format https://docs.knime.com/latest/python_installation_guide/index.html#usage-examples

You can also use Flow Variables and use them:

Help to use Python do insert variable in SQL code

@Aldemir you can export data from within the Python node as Flow Variables or as a dataframe (from a pandas dataframe). The code would look something like this: import knime.scripting.io as knio import numpy as np import pandas as pd # bring your string to a Flow Variable knio.flow_variables['var_txt_cbi'] = txt_cbi # bring your content to a pandas data frame output_table = pd.DataFrame({'column_txt_cbi': [txt_cbi]}) # bring the dataframe back to KNIME knio.output_tables[0] = knio.Table.f…

Here you can see a variety of options to work with KNIME and Python

Simple example to make a random forest model with new Python Scrip in KNIME...

If you want more complex things you can read about the use of additional Python packages to be managed with Conda:

KNIME and Python — Setting up and managing Conda environments

[JJV]

Thank you very much for taking the time and trouble to respond to me, it helps me a lot on my path that people like you help me.
The information you gave me was very helpful to me.

Thnks