cargo doc --open of pyo3

[wangjiawen2013]

Hi,
I wrote a python module using pyo3, but I find that I cannot generate the documentation using rust doc comments.
Cargo.toml:

[package]
name = "string-sum"
version = "0.1.0"
edition = "2018"

[lib]
name = "string_sum"
# "cdylib" is necessary to produce a shared library for Python to import from.
#
# Downstream Rust code (including code in `bin/`, `examples/`, and `tests/`) will not be able
# to `use string_sum;` unless the "rlib" or "lib" crate type is also included, e.g.:
# crate-type = ["cdylib", "rlib"]
crate-type = ["cdylib"]

[dependencies.pyo3]
version = "0.15.1"
features = ["extension-module"]

src/libs.rs:

use pyo3::prelude::*;

/// Formats the sum of two numbers as string.
#[pyfunction]
fn sum_as_string(a: usize, b: usize) -> PyResult<String> {
    Ok((a + b).to_string())
}

/// A Python module implemented in Rust. The name of this function must match
/// the `lib.name` setting in the `Cargo.toml`, else Python will not be able to
/// import the module.
#[pymodule]
fn string_sum(_py: Python, m: &PyModule) -> PyResult<()> {
    m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;

    Ok(())
}

Then I want to generate documenation using cargo doc --open, but what I saw is:

As you can see, it's very different from others rust crates documentation.

[davidhewitt]

What result are you expecting to get here? The functions you've defined are Python functions, so it seems correct to me that they don't have Rust API documentation.

[birkenfeld]

In 0.22 you also don't get the PyInit entry anymore.

However, when setting the functions as pub, you'll see them in rustdoc as expected.

So, I don't see a problem here.

[wangjiawen2013]

I mistakenly thought it will generate rust API documentation. Could I see the comments in the Python function/module ?

[birkenfeld]

You're not mistaken in that, but the functions need to be pub for that.

[wangjiawen2013]

Thank you, I can see it now!