fix support for custom types

Cargo.toml

@@ -12,10 +12,10 @@ documentation = "https://docs.rs/crate/pythonize/"
 
 [dependencies]
 serde = { version = "1.0", default-features = false, features = ["std"] }
-pyo3 = { version = "0.16.0", default-features = false }
+pyo3 = { version = "0.16.3", default-features = false }
 
 [dev-dependencies]
 serde = { version = "1.0", default-features = false, features = ["derive"] }
-pyo3 = { version = "0.16.0", default-features = false, features = ["auto-initialize", "macros", "pyproto"] }
+pyo3 = { version = "0.16.3", default-features = false, features = ["auto-initialize", "macros", "pyproto"] }
 serde_json = "1.0"
 maplit = "1.0.2"

src/de.rs

@@ -1,5 +1,4 @@
 use pyo3::types::*;
-use pyo3::{ffi, AsPyPointer, PyErr};
 use serde::de::{self, IntoDeserializer};
 use serde::Deserialize;
 
@@ -25,7 +24,7 @@ impl<'de> Depythonizer<'de> {
 
     fn sequence_access(&self, expected_len: Option<usize>) -> Result<PySequenceAccess<'de>> {
         let seq: &PySequence = self.input.downcast()?;
-        let len = seq.len()?;
+        let len = self.input.len()?;
 
         match expected_len {
             Some(expected) if expected != len => {
@@ -51,15 +50,6 @@ macro_rules! deserialize_type {
     };
 }
 
-fn seq_len(s: &PySequence) -> pyo3::PyResult<usize> {
-    let v = unsafe { ffi::PySequence_Size(s.as_ptr()) };
-    if v == -1 {
-        Err(PyErr::fetch(s.py()))
-    } else {
-        Ok(v as usize)
-    }
-}
-
 impl<'a, 'de> de::Deserializer<'de> for &'a mut Depythonizer<'de> {
     type Error = PythonizeError;
 
@@ -95,8 +85,8 @@ impl<'a, 'de> de::Deserializer<'de> for &'a mut Depythonizer<'de> {
             self.deserialize_tuple(obj.len()?, visitor)
         } else if obj.is_instance_of::<PyUnicode>()? {
             self.deserialize_str(visitor)
-        } else if let Ok(seq) = obj.downcast::<PySequence>() {
-            self.deserialize_tuple(seq_len(seq)?, visitor)
+        } else if let Ok(_) = obj.downcast::<PySequence>() {
+            self.deserialize_tuple(obj.len()?, visitor)
         } else if obj.downcast::<PyMapping>().is_ok() {
             self.deserialize_map(visitor)
         } else {

tests/test_custom_types.rs

@@ -1,12 +1,9 @@
-#![allow(deprecated)]
-
 use std::collections::HashMap;
 
 use pyo3::{
     exceptions::{PyIndexError, PyKeyError},
     prelude::*,
     types::{PyDict, PyList, PyMapping, PySequence},
-    PyMappingProtocol, PySequenceProtocol,
 };
 use pythonize::{
     depythonize, pythonize_custom, PythonizeDictType, PythonizeListType, PythonizeTypes,
@@ -18,8 +15,8 @@ struct CustomList {
     items: Vec<PyObject>,
 }
 
-#[pyproto]
-impl PySequenceProtocol for CustomList {
+#[pymethods]
+impl CustomList {
     fn __len__(&self) -> usize {
         self.items.len()
     }
@@ -75,13 +72,13 @@ fn test_custom_list() {
     })
 }
 
-#[pyclass]
+#[pyclass(mapping)]
 struct CustomDict {
     items: HashMap<String, PyObject>,
 }
 
-#[pyproto]
-impl PyMappingProtocol for CustomDict {
+#[pymethods]
+impl CustomDict {
     fn __len__(&self) -> usize {
         self.items.len()
     }
@@ -96,10 +93,7 @@ impl PyMappingProtocol for CustomDict {
     fn __setitem__(&mut self, key: String, value: PyObject) {
         self.items.insert(key, value);
     }
-}
 
-#[pymethods]
-impl CustomDict {
     fn keys(&self) -> Vec<&String> {
         self.items.keys().collect()
     }
@@ -129,7 +123,6 @@ impl PythonizeTypes for PythonizeCustomDict {
 }
 
 #[test]
-#[ignore]
 fn test_custom_dict() {
     Python::with_gil(|py| {
         let serialized =