Run In Notebook

Prerequisite

To quickly get started with Logica, ensure that Logica and Jupyter are installed locally on your system, or use Google Colab with Logica pre-installed. Additionally, you should install the following python packages to guarantee the usage

pip install duckdb pandas graphviz

WARNING

Without graphviz, you can still run Logica in a notebook, but the execution process visualization will be limited to an ASCII version instead of the full graphical representation.

Package Import

from logica import colab_logica

Cell Magic

Logica uses Cell Magic in Notebooks to support its Datalog-like syntax. To enable this feature, start the cell with %%logica. The first line of the cell should specify the predicates to be printed as output.

For example, to write a "Hello, World!" program in a Notebook, you can use:

%%logica Greeting
@Engine("sqlite");
Greeting("Hello World!");

After %%logica, specify the predicate to output, similar to Clingo's #show. Also, specify the engine to use. For more details, refer to the User Guide.

Result Interpretation

With such script, you will get the followings

From this, we know that the compiled query is stored in the Greeting_sql variable. The output of the Logica query is stored in a table variable named Greeting, which contains one row (0) and one column (col0) with the value Hello World!.