v0.3.1

Installing

If you have SWI-Prolog installed, it's just:

pip install pyswip==v0.3.1

See PySwip Getting Started for detailed instructions.

Documentation

Find the documentation for this version here.

Breaking Changes

Mandatory Keyword Arguments in Prolog Class

Some keyword arguments such as catcherrors used to be passable as positional arguments.
For instance the following was valid:

Prolog.assertz("big(airplane)", False)

Starting with v0.3.1, it is mandatory to pass arguments such as catcherrors as keyword arguments:

Prolog.assertz("big(airplane)", catcherrors=False)

Enhancements

Prolog.consult

Tilde character in paths are expanded to the user home directory

Prolog.consult("~/my_files/hanoi.pl")
# consults file /home/me/my_files/hanoi.pl

Both strings and pathlib.Path objects are allowed as paths

from pathlib import Path
Prolog.consult(Path("myfile.pl"))
# equivalent to:
Prolog.consult("myfile.pl")

Added relative_to keyword argument

relative_to keyword argument makes it easier to construct the consult path.
This keyword is no-op, if the consult path is absolute.

If the given relative_to path is a file, then the consult path is updated to become a sibling of that path.
Assume you have the /home/me/project/facts.pl that you want to consult from the run.py file which exists in the same directory /home/me/project.
Using the built-in __file__ constant which contains the path of the current Python file , it becomes very easy to do that:

# in run.py
Prolog.consult("facts.pl", relative_to=__file__)

If the given relative_path is a directory, then the consult path is updated to become a child of that path.

project_dir = "~/projects"
Prolog.consult("facts1.pl", relative_to=project_dir)
Prolog.consult("facts2.pl", relative_to=project_dir)

Symbolic links are not yet supported yet.

Prolog.dynamic

Updated Prolog.dynamic to accept one ore more terms:

Prolog.dynamic("mother/1", "father/1")