def _pathlist(self, key, arr):
        params = {}
        i = 0
        for value in arr:
            i += 1
            params["%s.%s" % (key, i)] = value
        return params
Tries to find a matcher callable associated to the given alias. If
dataset/ETHPy150Open secondstory/dewpoint/libcloud/drivers/ec2.py/EC2NodeDriver._pathlist--crossover with--dataset/ETHPy150Open drslump/pyshould/pyshould/matchers.py/lookup