add from_json

python/pydantic_core/_pydantic_core.pyi

@@ -41,6 +41,7 @@ __all__ = [
     'PydanticUndefinedType',
     'Some',
     'to_json',
+    'from_json',
     'to_jsonable_python',
     'list_all_errors',
     'TzInfo',
@@ -384,6 +385,22 @@ def to_json(
        JSON bytes.
     """
 
+def from_json(data: str | bytes | bytearray) -> Any:
+    """
+    Deserialize JSON data to a Python object.
+
+    This is effectively a faster version of [`json.loads()`][json.loads].
+
+    Arguments:
+        data: The JSON data to deserialize.
+
+    Raises:
+        ValueError: If deserialization fails.
+
+    Returns:
+        The deserialized Python object.
+    """
+
 def to_jsonable_python(
     value: Any,
     *,

src/lib.rs

@@ -4,6 +4,8 @@ extern crate core;
 
 use std::sync::OnceLock;
 
+use pyo3::exceptions::PyTypeError;
+use pyo3::types::{PyByteArray, PyBytes, PyString};
 use pyo3::{prelude::*, sync::GILOnceCell};
 
 // parse this first to get access to the contained macro
@@ -35,6 +37,19 @@ pub use serializers::{
 };
 pub use validators::{validate_core_schema, PySome, SchemaValidator};
 
+#[pyfunction]
+pub fn from_json(py: Python, obj: &PyAny) -> PyResult<PyObject> {
+    if let Ok(py_bytes) = obj.downcast::<PyBytes>() {
+        jiter::python_parse(py, py_bytes.as_bytes())
+    } else if let Ok(py_str) = obj.downcast::<PyString>() {
+        jiter::python_parse(py, py_str.to_str()?.as_bytes())
+    } else if let Ok(py_byte_array) = obj.downcast::<PyByteArray>() {
+        jiter::python_parse(py, &py_byte_array.to_vec())
+    } else {
+        Err(PyTypeError::new_err("Expected bytes, bytearray or str"))
+    }
+}
+
 pub fn get_pydantic_core_version() -> &'static str {
     static PYDANTIC_CORE_VERSION: OnceLock<String> = OnceLock::new();
 
@@ -94,6 +109,7 @@ fn _pydantic_core(py: Python, m: &PyModule) -> PyResult<()> {
     m.add_class::<SchemaSerializer>()?;
     m.add_class::<TzInfo>()?;
     m.add_function(wrap_pyfunction!(to_json, m)?)?;
+    m.add_function(wrap_pyfunction!(from_json, m)?)?;
     m.add_function(wrap_pyfunction!(to_jsonable_python, m)?)?;
     m.add_function(wrap_pyfunction!(list_all_errors, m)?)?;
     m.add_function(wrap_pyfunction!(validate_core_schema, m)?)?;