docs: Fix mismatch return value, remove redundant error propagation, and additional fixes (#4318)

* Fix mismatch return value, remove redundant error propagation, and fix typo

* Update guide/src/function/signature.md

Co-authored-by: Lily Foote <code@lilyf.org>

---------

Co-authored-by: Lily Foote <code@lilyf.org>

guide/src/ecosystem/async-await.md

@@ -129,9 +129,7 @@ fn rust_sleep(py: Python<'_>) -> PyResult<&Bound<'_, PyAny>> {
 
 #[pymodule]
 fn my_async_module(m: &Bound<'_, PyModule>) -> PyResult<()> {
-    m.add_function(wrap_pyfunction!(rust_sleep, m)?)?;
-
-    Ok(())
+    m.add_function(wrap_pyfunction!(rust_sleep, m)?)
 }
 ```
 
@@ -152,8 +150,7 @@ fn rust_sleep(py: Python<'_>) -> PyResult<&Bound<'_, PyAny>>> {
 
 #[pymodule]
 fn my_async_module(m: &Bound<'_, PyModule>) -> PyResult<()> {
-    m.add_function(wrap_pyfunction!(rust_sleep, m)?)?;
-    Ok(())
+    m.add_function(wrap_pyfunction!(rust_sleep, m)?)
 }
 ```
 
@@ -257,7 +254,7 @@ async def py_sleep():
 await_coro(py_sleep())
 ```
 
-If for you wanted to pass a callable function to the `#[pyfunction]` instead, (i.e. the last line becomes `await_coro(py_sleep))`, then the above example needs to be tweaked to first call the callable to get the coroutine:
+If you wanted to pass a callable function to the `#[pyfunction]` instead, (i.e. the last line becomes `await_coro(py_sleep))`, then the above example needs to be tweaked to first call the callable to get the coroutine:
 
 ```rust
 #[pyfunction]

guide/src/function.md

@@ -14,8 +14,7 @@ fn double(x: usize) -> usize {
 
 #[pymodule]
 fn my_extension(m: &Bound<'_, PyModule>) -> PyResult<()> {
-    m.add_function(wrap_pyfunction!(double, m)?)?;
-    Ok(())
+    m.add_function(wrap_pyfunction!(double, m)?)
 }
 ```
 
@@ -56,8 +55,7 @@ The `#[pyo3]` attribute can be used to modify properties of the generated Python
 
     #[pymodule]
     fn module_with_functions(m: &Bound<'_, PyModule>) -> PyResult<()> {
-        m.add_function(wrap_pyfunction!(no_args_py, m)?)?;
-        Ok(())
+        m.add_function(wrap_pyfunction!(no_args_py, m)?)
     }
 
     # Python::with_gil(|py| {
@@ -113,8 +111,7 @@ The `#[pyo3]` attribute can be used on individual arguments to modify properties
     use pyo3::prelude::*;
 
     fn get_length(obj: &Bound<'_, PyAny>) -> PyResult<usize> {
-        let length = obj.len()?;
-        Ok(length)
+        obj.len()
     }
 
     #[pyfunction]
@@ -204,8 +201,7 @@ fn my_extension(m: &Bound<'_, PyModule>) -> PyResult<()> {
         x * 2
     }
 
-    m.add_function(wrap_pyfunction!(double, m)?)?;
-    Ok(())
+    m.add_function(wrap_pyfunction!(double, m)?)
 }
 ```
 

guide/src/function/signature.md

@@ -22,8 +22,7 @@ fn num_kwds(kwds: Option<&Bound<'_, PyDict>>) -> usize {
 
 #[pymodule]
 fn module_with_functions(m: &Bound<'_, PyModule>) -> PyResult<()> {
-    m.add_function(wrap_pyfunction!(num_kwds, m)?).unwrap();
-    Ok(())
+    m.add_function(wrap_pyfunction!(num_kwds, m)?)
 }
 ```
 

guide/src/getting-started.md

@@ -159,8 +159,7 @@ fn sum_as_string(a: usize, b: usize) -> PyResult<String> {
 /// import the module.
 #[pymodule]
 fn pyo3_example(m: &Bound<'_, PyModule>) -> PyResult<()> {
-    m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
-    Ok(())
+    m.add_function(wrap_pyfunction!(sum_as_string, m)?)
 }
 ```
 

guide/src/module.md

@@ -13,8 +13,7 @@ fn double(x: usize) -> usize {
 /// This module is implemented in Rust.
 #[pymodule]
 fn my_extension(m: &Bound<'_, PyModule>) -> PyResult<()> {
-    m.add_function(wrap_pyfunction!(double, m)?)?;
-    Ok(())
+    m.add_function(wrap_pyfunction!(double, m)?)
 }
 ```
 
@@ -35,8 +34,7 @@ fn double(x: usize) -> usize {
 #[pymodule]
 #[pyo3(name = "custom_name")]
 fn my_extension(m: &Bound<'_, PyModule>) -> PyResult<()> {
-    m.add_function(wrap_pyfunction!(double, m)?)?;
-    Ok(())
+    m.add_function(wrap_pyfunction!(double, m)?)
 }
 ```
 
@@ -80,8 +78,7 @@ fn parent_module(m: &Bound<'_, PyModule>) -> PyResult<()> {
 fn register_child_module(parent_module: &Bound<'_, PyModule>) -> PyResult<()> {
     let child_module = PyModule::new_bound(parent_module.py(), "child_module")?;
     child_module.add_function(wrap_pyfunction!(func, &child_module)?)?;
-    parent_module.add_submodule(&child_module)?;
-    Ok(())
+    parent_module.add_submodule(&child_module)
 }
 
 #[pyfunction]
@@ -143,8 +140,7 @@ mod my_extension {
     #[pymodule_init]
     fn init(m: &Bound<'_, PyModule>) -> PyResult<()> {
         // Arbitrary code to run at the module initialization
-        m.add("double2", m.getattr("double")?)?;
-        Ok(())
+        m.add("double2", m.getattr("double")?)
     }
 }
 # }