#[pyclass] can be used with the following parameters:
| Parameter | Description |
|---|---|
crate = "some::path" |
Path to import the pyo3 crate, if it's not accessible at ::pyo3. |
dict |
Gives instances of this class an empty __dict__ to store custom attributes. |
extends = BaseType |
Use a custom baseclass. Defaults to [PyAny][params-1] |
freelist = N |
Implements a [free list][params-2] of size N. This can improve performance for types that are often created and deleted in quick succession. Profile your code to see whether freelist is right for you. |
mapping |
Inform PyO3 that this class is a [Mapping][params-mapping], and so leave its implementation of sequence C-API slots empty. |
module = "module_name" |
Python code will see the class as being defined in this module. Defaults to builtins. |
name = "python_name" |
Sets the name that Python sees this class as. Defaults to the name of the Rust struct. |
text_signature = "(arg1, arg2, ...)" |
Sets the text signature for the Python class' __new__ method. |
subclass |
Allows other Python classes and #[pyclass] to inherit from this class. Enums cannot be subclassed. |
unsendable |
Required if your struct is not [Send][params-3]. Rather than using unsendable, consider implementing your struct in a threadsafe way by e.g. substituting [Rc][params-4] with [Arc][params-5]. By using unsendable, your class will panic when accessed by another thread. |
weakref |
Allows this class to be [weakly referenceable][params-6]. |
All of these parameters can either be passed directly on the #[pyclass(...)] annotation, or as one or
more accompanying #[pyo3(...)] annotations, e.g.:
// Argument supplied directly to the `#[pyclass]` annotation.
#[pyclass(name = "SomeName", subclass)]
struct MyClass { }
// Argument supplied as a separate annotation.
#[pyclass]
#[pyo3(name = "SomeName", subclass)]
struct MyClass { }