Got a AttributeError: 'Rule' object has no attribute '__name__'

[wangyingsm]

Background, I am new to Pyknow. I want to build a expert system to auto calculate a cell quality score based on some parameters. The score algorithm should be loaded from a json data, such like:

	{
		"PN": [{
			"condition": "pn",
			"symbol": "=",
			"value": "2PN",
			"score": "20",
			"weight": "1.0"
		}, {
			"condition": "time",
			"symbol": "<=",
			"value": "12",
			"score": "20",
			"weight": "1.0"
		}],
		"4C": [{
			"condition": "cell",
			"symbol": "=",
			"value": "4C",
			"score": "20",
			"weight": "1.0"
		}, {
			"condition": "even",
			"symbol": "=",
			"value": true,
			"score": "20",
			"weight": "1.0"
		}, {
			"condition": "fragment",
			"symbol": "=",
			"value": "<5%",
			"score": "20",
			"weight": "1.0"
		}, {
			"condition": "fragment",
			"symbol": "=",
			"value": "5%-10%",
			"score": "15",
			"weight": "1.0"
		}, {
			"condition": "fragment",
			"symbol": "=",
			"value": "10%-20%",
			"score": "10",
			"weight": "1.0"
		}, {
			"condition": "time",
			"symbol": "<=",
			"value": "36",
			"score": "20",
			"weight": "1.0"
		}]
	}

Here are my codes for this,

	from pyknow import *
	from functools import partial

	class EmbryoScore(KnowledgeEngine):
	    score = 0
	    @classmethod
	    def removeAllRules(cls):
	        for m in [attr for attr in cls.__dict__ if attr.startswith('rule')]:
	            delattr(cls, m)

	def parse_json_rules(rule_json):
	    import json
	    rules = json.loads(rule_json)
	    sal = 100
	    index = 0
	    for stage in rules:
	        for rule_item in rules[stage]:
	            rule = {'condition': rule_item['condition']}
	            rule['stage'] = stage
	            if rule_item['symbol'] not in ('=', '<', '<=', '>', '>='):
	                continue
	            def _cond(value, symbol):
	                if symbol == '=': return EQ(value)
	                if symbol == '<': return LT(value)
	                if symbol == '<=': return LE(value)
	                if symbol == '>': return GT(value)
	                if symbol == '>=': return GE(value)

	            def _add(self, **kwargs):
	                if 'score' not in kwargs or 'weight' not in kwargs:
	                    raise ValueError('No score or weight specified')
	                s, w = int(kwargs['score']), float(kwargs['weight'])
	                self.score += s * w
	        
	            R = Rule(AND(Fact(**rule, value=MATCH.value & 
                        _cond(rule_item['value'], rule_item['symbol']))),
	                    salience=sal)(partial(_add, score=rule_item['score'], 
                        weight=rule_item['weight']))
	            setattr(EmbryoScore, f'rule{index}', R)
	            index += 1
	            sal -= 1

	def init_engine(rule_json):
	    EmbryoScore.removeAllRules()
	    parse_json_rules(rule_json)
	    engine = EmbryoScore()
	    engine.reset()
	    return engine

	import unittest

	class ScoreTest(unittest.TestCase):
		def test(self):
			engine = init_engine(rule_json)
			engine.declare(Fact(condition='pn', stage='PN', value='2PN'))
			engine.declare(Fact(stage='4C', condition='cell', value='4C'))
			engine.declare(Fact(stage='4C', condition='fragment', value='10%-20%'))
			engine.declare(Fact(stage='4C', condition='time', value='32'))
			engine.run()
			self.assertEqual(engine.score, 70)


	if __name__ == '__main__':
	    unittest.main()

It raises a AttributeError: 'Rule' object has no attribute 'name' when engine.run() on engine.py line 162

	watchers.RULES.info(
         "FIRE %s %s: %s",
         execution,
         activation.rule.__name__,
         ", ".join(str(f) for f in activation.facts))

I can't find out what the problem is. Wonder if I can get some help here. THANKS.

[nilp0inter]

Hi,

the error you are receiving is due to the usage of partial functions in the RHS of the rule.

You can solve this using a closure instead of a partial function:

            def _add_partial(score, weight):
                def _add(self, **kwargs):
                    s, w = int(score), float(weight)
                    self.score += s * w
                return _add

            R = Rule(AND(Fact(**rule, value=MATCH.value & 
                    _cond(rule_item['value'], rule_item['symbol']))),
                    salience=sal)(_add_partial(score=rule_item['score'], 
                                               weight=rule_item['weight']))

Hope this help!

[wangyingsm]

Hi,

the error you are receiving is due to the usage of partial functions in the RHS of the rule.

You can solve this using a closure instead of a partial function:

            def _add_partial(score, weight):
                def _add(self, **kwargs):
                    s, w = int(score), float(weight)
                    self.score += s * w
                return _add

            R = Rule(AND(Fact(**rule, value=MATCH.value & 
                    _cond(rule_item['value'], rule_item['symbol']))),
                    salience=sal)(_add_partial(score=rule_item['score'], 
                                               weight=rule_item['weight']))

Hope this help!

Wow. It DOES WORK.
THANKS.