RightTyper is a Python tool that generates types for your function arguments and return values.
RightTyper lets your code run at nearly full speed (around 30% overhead) and little memory overhead.
As a result, you won't experience slowdowns in your code or large memory consumption while using it,
allowing you to integrate it with your standard tests and development process.
By virtue of its design, and in a significant departure from previous approaches, RightTyper only captures the most commonly used types,
letting a type checker like mypy detect possibly incorrect type mismatches in your code.
You can run RightTyper with arbitrary Python programs and it will generate types for every function that gets executed. It works great in combination with pytest:
python3 -m righttyper run -m pytest --continue-on-collection-errors /your/test/dirIn addition to generating types, RightTyper has the following features:
- It efficiently computes type annotation "coverage" for a file or directory of files
- It infers shape annotations for NumPy/JAX/PyTorch tensors, compatible with
jaxtypingandbeartypeortypeguard.
For details about how RightTyper works, please see the following paper: RightTyper: Effective and Efficient Type Annotation for Python.
The graph below presents the overhead of using RightTyper versus two previous tools, PyAnnotate and MonkeyType, across a range of benchmarks. On average, RightTyper imposes only 30% overhead compared to running plain Python. On running the tests of a popular package (black), RightTyper imposes only 20% overhead, while MonkeyType slows down execution by over 6x. In extreme cases, MonkeyType runs over 270x slower than RightTyper.
Install RightTyper from pip as usual:
python3 -m pip install righttyperTo use RightTyper, simply run your script with python3 -m righttyper run instead of python3:
python3 -m righttyper run your_script.py [args...]This will execute your_script.py with RightTyper's monitoring
enabled. The type signatures of all functions will be recorded and
output to a file named righttyper.out. The file contains, for every
function, the signature, and a diff of the original function with the
annotated version. It also optionally (with the --infer-shapes flag)
generates jaxtyping-compatible shape
annotations for NumPy/JAX/PyTorch tensors. Below is an example:
test-hints.py:
==============
barnacle
- def barnacle(x):
+ def barnacle(x: jaxtyping.Float64[np.ndarray, "10 D1"]) -> jaxtyping.Float64[np.ndarray, "D1"]:
fooq
- def fooq(x: int, y) -> bool:
+ def fooq(x: int, y: int) -> bool:
? +++++To add type hints directly to your code, use this command:
python3 -m righttyper run --output-files --overwrite your_script.py [args...]To do the same with pytest:
python3 -m righttyper run --output-files --overwrite -m pytest [pytest-args...]RightTyper may infer types that include deeply nested generics.
While such precise types improve recall in type checking, they can be difficult for developers to read and understand.
To improve the ergonomics of such annotations, RightTyper offers a --type-depth-limit option to specify the maximum
number of levels to include in type.
For example, with --type-depth-limit=1, a type inferred as list[tuple[tuple[int, int]]] would be emitted as list[tuple] instead.
Below is the full list of options for the run command:
$ python3 -m righttyper run --help
Usage: python -m righttyper run [OPTIONS] [SCRIPT] [ARGS]...
Runs a given script or module, collecting type information.
Options:
-m, --module TEXT Run the given module instead of a script.
--all-files Process any files encountered, including
libraries (except for those specified in
--include-files)
--include-files REGEX Process only files matching the given
regular expression. Can be passed multiple
times.
--include-functions REGEX Only annotate functions matching the given
regular expression. Can be passed multiple
times.
--infer-shapes Produce tensor shape annotations (compatible
with jaxtyping).
--root DIRECTORY Process only files under the given
directory. If omitted, the script's
directory (or, for -m, the current
directory) is used.
--overwrite / --no-overwrite Overwrite ".py" files with type information.
If disabled, ".py.typed" files are written
instead. The original files are saved as
".bak". [default: overwrite]
--output-files / --no-output-files
Output annotated files (possibly
overwriting, if specified). If disabled,
the annotations are only written to
righttyper.out. [default: output-files]
--ignore-annotations Ignore existing annotations and overwrite
with type information.
--only-update-annotations Overwrite existing annotations but never add
new ones.
--generate-stubs Generate stub files (.pyi).
--json-output Output inferences in JSON, instead of
writing righttyper.out.
--target-overhead FLOAT Target overhead, as a percentage (e.g., 5).
[default: 5.0]
--use-multiprocessing / --no-use-multiprocessing
Whether to use multiprocessing. [default:
use-multiprocessing]
--sampling / --no-sampling Whether to sample calls or to use every one.
[default: sampling]
--no-sampling-for REGEX Rather than sample, record every invocation
of any functions matching the given regular
expression. Can be passed multiple times.
--replace-dict / --no-replace-dict
Whether to replace 'dict' to enable
efficient, statistically correct samples.
[default: no-replace-dict]
--container-sample-limit INTEGER
Number of container elements to sample.
[default: 1000]
--type-depth-limit [INTEGER|none]
Maximum depth (types within types) for
generic types; 'none' to disable. [default:
none]
--python-version [3.9|3.10|3.11|3.12|3.13]
Python version for which to emit
annotations. [default: 3.12]
--use-top-pct PCT Only use the PCT% most common call traces.
[default: 80; 1<=x<=100]
--only-collect Rather than immediately process collect
data, save it to righttyper.rt. You can
later process using RightTyper's "process"
command.
--resolve-mocks / --no-resolve-mocks
Whether to attempt to resolve test types,
such as mocks, to non-test types. [default:
no-resolve-mocks]
--exclude-test-types / --no-exclude-test-types
Whether to exclude or replace with
"typing.Any" types defined in test modules.
[default: exclude-test-types]
--test-modules MODULE Additional modules (besides those detected)
whose types are subject to mock resolution
or test type exclusion, if enabled. Matches
submodules as well. Can be passed multiple
times. [default: pytest, _pytest, py.test,
unittest]
--use-typing-never / --no-use-typing-never
Whether to emit "typing.Never". [default:
use-typing-never]
--adjust-type-names / --no-adjust-type-names
Whether to look for a canonical name for
types, rather than use the module and name
where they are defined. [default: adjust-
type-names]
--debug Include diagnostic information in log file.
--help Show this message and exit.