Python Long String Comparison Function needed

The purpose of the function is to import 1,000,000 strings with an average of 15-20 chars and filter the list down based on comparing the unique chars and a proprietary equation that I have supplied below. The end result should be a much smaller list of possible matches where the truncated records do not meet the scoring requirements. First, we will need a function that will take 3 inputs: defined_score as a decimal and 2 strings as input and compare them. The purpose is to find the characters that are not in each string. You miht try converting the column using set(). Just an idea. The output of this function will be based on this equation: (1/3 * ("unique characters of string1" / LEN(string1)) +("unique characters of string2 / LEN(string2)) + 1) . The result of this equation we will call the comparison_score. It should be a decimal. Speed is of the upmost importance only second to accuracy. I recommend/need the function to by multiprocessing as well as using bitwise calculation. The target speed is to process a column of 1,000,000 strings with an average of 20 characters in less than 5 minutes. In addition, we must minimize the RAM that this process needs, so your function must monitory RAM consumption and should employ in-memory and flat file logic so that no more than 2GB are used on processing 1,000,000 records. Regarding output, we should only return values when the comparison_score is bigger than the defined_score as well as save the returned values to a json file. It in important to mention that each record can only be listed once in the file. There should be no duplicate records. I will also need logic that will take a JSON file (we can use excel for testing) and will process it based on the above requirement. Please only bid on this if you really know what you are doing. Please do not think you can use ChatGPT to do this. I already went that route and tried for several hours. The best ChatGPT was 60 records per second and I need 3,500 per second. If you are interested, it is possible this project could lead to a permanent position on my team. Include watermelon in your bid so I know you are not a bot.