How can i create a java udf or python udf

i wanted to know how can i create a java udf or python udf, can some explain in detail step by step procedure

Here’s an example of java udf: GitHub - dremio-hub/dremio-internal-function-example
For python udf, see this.

where should i run this java jar file, can you please say in detail

Its mentioned in the readme: It can be used by copying the built jar file into the Dremio jars directory.