Use the results

run returns a RumoResults object. This object has one table for each predicate.

Column names

Rumo uses the variable names in the heads of the rules as column names. For example, this rule gives the columns name and score:

good(?name, ?score) :- ...

If a column has no variable name, Rumo uses col0, col1, and so on. This occurs for imported predicates and for constants in rule heads.

If more than one rule calculates the same predicate, Rumo uses the first available name for each column.

To set different column names, use the columns argument:

results.to_pandas("good", columns=["person", "points"])

The number of names must be the same as the number of columns. If it is not, Rumo raises a ValueError.

Get a pandas DataFrame

df = results.to_pandas("good")

This method needs pandas.

Get a Polars DataFrame

df = results.to_polars("good")

Get a list of dictionaries

rows = results.to_dicts("good")
# [{'name': 'Bob', 'score': 92.0}, {'name': 'Dave', 'score': 95.1}]

Get a list of tuples

rows = results.rows("good")
# [('Bob', 92.0), ('Dave', 95.1)]

Get all the results

to_dict returns a dictionary with one list of dictionaries for each predicate:

results.to_dict()
# {'good': [{'name': 'Bob', 'score': 92.0}, ...]}

Omit the predicate name

If the results have only one predicate, you can omit the predicate name:

results.to_pandas()

If the results have more than one predicate, you must give the name. If you do not, Rumo raises a ValueError.

Use the results as a mapping

A RumoResults object operates like a read-only dictionary:

results.predicates()     # ['good']
results.columns("good")  # ['name', 'score']
"good" in results        # True
len(results)             # 1
for predicate in results:
    print(predicate, results[predicate])

results["good"] returns a list of dictionaries. If the predicate does not exist, it raises a KeyError.

Value types

Rumo converts each nemo value to a Python value:

Note: Turtle reads numbers such as 88.5 as xsd:decimal. Thus, numbers from a DataFrame become float values in the results.