Implement #[init] method attribute in #[pymethods]
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ahlinc
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This allows to control objects initialization flow in the Rust code in case of inheritance from native Python types.
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It seems that most of |
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My apologies for the delay. Thanks for this, it seems useful 👍
Please add some more tests, for stuff like combinations of attributes:
#[init]
#[classmethod]
#[init]
#[new]
and a pyclass that inherits another pyclass, that init cannot be on functions and so on.
| explicitly like that happens in a regular Python code. | ||
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| To declare an initializer, you need to define a method and annotate it with the `#[init]` | ||
| attribute. An `init` method must have the same input paretemeters signature like |
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| attribute. An `init` method must have the same input paretemeters signature like | |
| attribute. An `init` method must have the same input parameters signature like |
| `__init__` method of `PyDict` been called. In this case by defining an own `init` method | ||
| it's possible to stop initialization flow. | ||
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| If you declare an own `init` method you may need to call a super class `__init__` method |
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| If you declare an own `init` method you may need to call a super class `__init__` method | |
| If you declare an own `init` method you may need to call a super class' `__init__` method |
| @@ -830,7 +842,6 @@ impl<'a> FnSpec<'a> { | |||
| _kwargs: *mut #pyo3_path::ffi::PyObject | |||
| ) -> #pyo3_path::PyResult<*mut #pyo3_path::ffi::PyObject> { | |||
| use #pyo3_path::impl_::callback::IntoPyCallbackOutput; | |||
| let function = #rust_name; // Shadow the function name to avoid #3017 | |||
| @@ -104,6 +106,35 @@ impl ClassWithDict { | |||
| } | |||
| } | |||
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| #[cfg(Py_3_8)] | |||
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Is #[init] only supported on 3.8 and up? Please also document this in the guide.
| @@ -181,6 +182,59 @@ created from Rust, but not from Python. | |||
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| For arguments, see the [`Method arguments`](#method-arguments) section below. | |||
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| ## Initializer | |||
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Please also document that it shall return either PyResult<()> or nothing. Ideally the macro would check for this; not sure how feasible that is.
| @@ -181,6 +182,59 @@ created from Rust, but not from Python. | |||
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| For arguments, see the [`Method arguments`](#method-arguments) section below. | |||
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| ## Initializer | |||
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| An initializer implements Python's `__init__` method. | |||
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We should discourage users from using init unless they really need it; they probably should use new instead.
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| Like in the constructor case the Rust method name isn't important. | ||
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| ```rust,ignore |
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Why is this ignored? Please write some test code in this example. It can be something simple like a hidden test that just creates and checks it.
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btw I also have basic support for defining
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This allows to control objects initialization flow in the Rust code in case of inheritance from native Python types.
A simple example, you implement a class inherited from
PyDictbut want to build a custom constructor interface. With just the#[new]constructor it's not possible and the basePyDict__init__method will be called too with all arguments that were passed to the constructor as a standard objects initialization behavior.