简单的Python规则匹配

Question

I'm attempting to create a simple rule matching engine where if any rules match from a dictionary:

{'id': [{'status1' : 'v1'}  , {'status3' : 'v2'} , {'status1' : 'v2'}] }

and the rules are:

{'rule1': {'status1': ['v1'], 'status2': ['v2' , 'v3']},
              'rule2': {'status1': ['v2'], 'status2': ['v4']}}

The rule matching should produce the output:

[('status1', 'v1', ['v1'], 'rule1'), ('status1', 'v2', ['v2'], 'rule2')]

('status1', 'v1', ['v1'], 'rule1') corresponds to status1 matching on rule1 as rule1 contains the value v1 for status1

('status1', 'v2', ['v2'], 'rule2') corresponds to status1 matching on rule2 as rule2 contains the value v2 for status1

Here is the code I've written:

values_to_validate = {'id': [{'status1' : 'v1'}  , {'status3' : 'v2'} , {'status1' : 'v2'}] }

rule_set_1 = {'rule1': {'status1': ['v1'], 'status2': ['v2' , 'v3']},
              'rule2': {'status1': ['v2'], 'status2': ['v4']}}

class RulesConfig() :
    
    def __init__(self , rules):
        self.rules = rules

    def get_rule_names(self):
        return self.rules.keys()
    
    def get_conditions_for_rule(self, rule_name):
        return self.rules[rule_name]
    
    def get_matched_rules(self, values_to_validate):
        is_matched = False
        matched_rules = []
        for v in values_to_validate.values() : 
            for rk,rv in self.rules.items() :
                for a in v : 
                    for d,f in a.items() : 
                        if d in rv : 
                            matched_rules.append((d,f , rv[d] , rk))

        return matched_rules

    
v = RulesConfig(rule_set_1)
print(v.get_matched_rules(values_to_validate))

which returns:

[('status1', 'v1', ['v1'], 'rule1'), ('status1', 'v2', ['v1'], 'rule1'),
 ('status1', 'v1', ['v2'], 'rule2'), ('status1', 'v2', ['v2'], 'rule2')]

To return the expected output I could remove duplicated entries in the above list of tuples but I think there is a mistake in my algorithm.

The code I use to find the matched rules:

def get_matched_rules(self, values_to_validate):
    is_matched = False
    matched_rules = []
    for v in values_to_validate.values() : 
        for rk,rv in self.rules.items() :
            for a in v : 
                for d,f in a.items() : 
                    if d in rv : 
                        matched_rules.append((d,f , rv[d] , rk))

seems unnecessary complex, is there an idiomatic preferred Python method of solving this type of problem? I'm using Python 3.6 and do not want to include libraries that are not included as part of standard Python interpreter.

Answer 1

This test is insufficient:

if d in rv : 
    matched_rules.append((d,f , rv[d] , rk))

This will check only if 'status1' for example is in the rule dictionary, you also need to check whether it has the right value:

if d in rv and f in rv[d]: 
    matched_rules.append((d,f , rv[d] , rk))