I encounter strange behaviour in constructor of a python class:

class MetricQuery():
    query = None

    def __init__(self, query = None):
        self.query = query

    @classmethod
    def sum(self, field, response_field = None):
        self.es_query = basic_aggregation("sum", field, response_field)
        return self

    @classmethod
    def get(self):
        output = self.es_query
        if self.query != None: output["query"] = self.query["query"]
        return output

Here's the test method for sum:

def test_sum():
    query = {"query": {"match": {"active": True}}}
    assert MetricQuery(query).sum("visits").get() == {"query": {"match": {"active": True}},"aggs": {"sum_visits_field": {"sum": {"field": "visits"}}}}

Test fails, saying that right contains 1 more item, "query".

It seems constructor can't set query value properly. What am I missing?

CodePudding user response：

It looks like there is a missing quotation mark at the end of the definition of query in your test method:

Your Code query = {"query": {"match": {"active": True}}

This should be: query = {"query": {"match": {"active": True}}}

This is causing a syntax error, and as a result, the value of the query is not being set correctly.

If you fix this syntax error, your test should pass.

CodePudding user response：

As @jasonharper mentioned in the comment, I confused classmethod and a regular method. (I'm new to python)

I removed all classmethod definitions and call the class as follows (to write a one line code):

def test_avg():
    assert (MetricQuery()).avg("age", "my_result_field").get() == {"aggs": {"my_result_field": {"avg": {"field": "age"}}}}

Now all works fine.

I develop an Elasticsearch aggregation library, hope it'll be useful when I can complete.