Typerwriter

Typerwriter is a Python tool that generates types for your function arguments and return values. It produces much the same results as Instagram's monkeytype, while being both more flexible and vastly more efficient. Unlike monkeytype, which can slow down your code more than tenfold and cause it to consume huge amounts of memory, typerwriter lets your code run at nearly full speed with almost no memory overhead.

typerwriter: high performance

In the below example drawn from the pyperformance benchmark suite, monkeytype runs 30x slower than the original program or when running with typerwriter (which runs under 3% slower).

% python3 bm_mdp          
Time elapsed:  6.106977417017333
% typerwriter bm_mdp
Time elapsed:  6.299191833997611
% monkeytype run bm_mdp
Time elapsed:  184.57902495900635

typerwriter: low memory consumption

With monkeytype, this program also consumes 5GB of RAM; the original consumes just 21MB. That's an over 200x increase in memory consumption. monkeytype also leaves behind a 3GB SQLite file.

By contrast, typerwriter's memory consumption is just a small increment over the original program: it consumes about 24MB, just 15% more.

NOTE: this is an alpha release and is not production ready.

Requirements

• Python 3.12 or higher

Installation

python3 -m pip install typerwriter

Usage

To use Typerwriter, simply run your script with typerwriter instead of python3:

typerwriter your_script.py [args...]

This will execute your_script.py with Typerwriter's monitoring enabled. The type signatures of all functions will be recorded and output to a file named typerwriter.out. Each line represents a function signature in the following format:

filename:def function_name(arg1: arg1_type, arg2: arg2_type, ...) -> return_type

Contributing

Contributions are welcome! Feel free to submit pull requests or report issues on the GitHub repository.

License

This project is licensed under the Apache License. See the LICENSE file for details.