input: Write a python function to parse a string into a dictionary.
  assert parse_string("bio: John Smith, age: 32") == {"bio": "John Smith", "age": "32"}
  assert parse_string("name: Alice, country: Wonderland") == {"name": "Alice", "country": "Wonderland"}
  assert parse_string("fruit: Apple, color: Red, price: 1.2") == {"fruit": "Apple", "color": "Red", "price": "1.2"}
output: def parse_string(s):
      result = {}
      pairs = s.split(", ")
      for pair in pairs:
          key, value = pair.split(": ")
          result[key] = value
      return result