goal_dict.py

GaTransactionConf = namedtuple("GaTransactionConf", ["sku", "name", "category"])

class GaTransactionsDict(dict):
       
    def __getitem__(self, key):
        if isinstance(key, GaTransactionConf):
            updated = False
            for mapping in self.keys():
                if cmp_ga_conf(key, mapping):
                    key = mapping #update the key
                    updated = True
                    break # should we break??
            if not updated:
                  raise KeyError("not found")
        return dict.__getitem__(self, key)
        
def cmp_ga_conf(record, goal_mapping):
    if ((goal_mapping.sku is None or record.sku in goal_mapping.sku) and 
        (goal_mapping.name is None or record.name in goal_mapping.name) and
        (goal_mapping.category is None or record.category in goal_mapping.category)):
        return True
    else:
        return False
        
        
a = GaTransactionConf(sku=(1,2), name=(3,4), category=None)

goal_dict = GaTransactionsDict({a:1})
print goal_dict

b = GaTransactionConf(sku=(1,2),  name=(3,4), category=None)

assert goal_dict[b] is goal_dict[a]


c = GaTransactionConf(sku=1,name=3,category=None)

assert goal_dict[c] == goal_dict[a]

The return dict.__getitem__(self, key) will raise the KeyError for us. Just need to break (and whether we break or not is irrelevant... if we have 2 mappings that match the goal, the way we have it working now this is a user mistake)