input: Write a function to parse a JSON string into a Python dictionary.
  assert parse_json('{"movie": "Star Wars","genre": "Action"}') == {'movie': 'Star Wars', 'genre': 'Action'}
  assert parse_json('{"name": "John", "age": 30, "city": "New York"}') == {'name': 'John', 'age': 30, 'city': 'New York'}
  assert parse_json('{"a": 1, "b": 2, "c": 3}') == {'a': 1, 'b': 2, 'c': 3}
output: def parse_json(json_string):
      import json
      return json.loads(json_string)