import json

x = {
  "name": "Ken",
  "age": 45,
  "married": True,
  "children": ("Alice","Bob"),
  "pets": ['Dog'],
  "cars": [
    {"model": "Audi A1", "mpg": 15.1},
    {"model": "Zeep Compass", "mpg": 18.1}
  ]
}
# sorting result in asscending order by keys:
sorted_string = json.dumps(x, indent=4, sort_keys=True)
print(sorted_string)