If py_call/2
or one of the other predicates that access Python causes Python to raise
an exception, this exception is translated into a Prolog exception of
the shape below. The library defines a rule for
print_message/2
to render these errors in a human readable way.
error(python_error(ErrorType, Value, Stack), _)
Here, ErrorType is the name of the error type, as an atom,
e.g.,
’TypeError'. Value is the exception object
represented by a Python object reference. Stack is either @none
or an object that captures the Python stack. The library(janus)
defines the message formatting, which makes us end up with a message
like below.
?- py_call(nomodule:noattr).
ERROR: Python 'ModuleNotFoundError':
ERROR: No module named 'nomodule'
ERROR: In:
ERROR: [10] janus:py_call(nomodule:noattr)
