Lazy conversion of dictionary to JSON string

lazy_dict_str.py

import json
import logging
import time

logger = logging.getLogger()

d = {"A": 1, "B": 2, "C": {'a': 'hello', "_": 'world'}}

class LazyDictStr:
    "Converts dictionary to formatted JSON string when str(...) called"
    def __init__(self, dictionary: dict):
        self.dictionary = dictionary

    def __str__(self):
        return json.dumps(self.dictionary, indent=2)

logger.warning("This is a dictionary:\n%s", LazyDictStr(d))  # dict is converted
logger.debug("This is a dictionary:\n%s", LazyDictStr(d))  # dict is NOT converted

a = time.perf_counter()
for i in range(100000):
    j = LazyDictStr(d)
print("No conversion", time.perf_counter() - a)

a = time.perf_counter()
for i in range(100000):
    j = json.dumps(d, indent=2)
print("Direct conversion", time.perf_counter() - a)

a = time.perf_counter()
for i in range(100000):
    j = str(LazyDictStr(d))
print("Lazy conversion", time.perf_counter() - a)