nautilus_core/python/
params.rs

1// -------------------------------------------------------------------------------------------------
2//  Copyright (C) 2015-2026 Nautech Systems Pty Ltd. All rights reserved.
3//  https://nautechsystems.io
4//
5//  Licensed under the GNU Lesser General Public License Version 3.0 (the "License");
6//  You may not use this file except in compliance with the License.
7//  You may obtain a copy of the License at https://www.gnu.org/licenses/lgpl-3.0.en.html
8//
9//  Unless required by applicable law or agreed to in writing, software
10//  distributed under the License is distributed on an "AS IS" BASIS,
11//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12//  See the License for the specific language governing permissions and
13//  limitations under the License.
14// -------------------------------------------------------------------------------------------------
15
16//! Python bindings for [`Params`] type conversion.
17
18use indexmap::IndexMap;
19use pyo3::{
20    conversion::IntoPyObjectExt,
21    prelude::*,
22    types::{PyDict, PyList, PyModule},
23};
24use serde_json::Value;
25
26use crate::{params::Params, python::to_pyvalue_err};
27
28/// Converts a Python dict to `Params` (IndexMap<String, Value>).
29///
30/// # Errors
31///
32/// Returns a `PyErr` if:
33/// - the dict cannot be serialized to JSON
34/// - the JSON is not a valid object
35pub fn pydict_to_params(py: Python<'_>, dict: Py<PyDict>) -> PyResult<Option<Params>> {
36    let dict_bound = dict.bind(py);
37    if dict_bound.is_empty() {
38        return Ok(None);
39    }
40
41    let json_str: String = PyModule::import(py, "json")?
42        .call_method("dumps", (dict,), None)?
43        .extract()?;
44    let json_value: Value = serde_json::from_str(&json_str).map_err(to_pyvalue_err)?;
45
46    if let Value::Object(map) = json_value {
47        Ok(Some(Params::from_index_map(
48            map.into_iter().collect::<IndexMap<String, Value>>(),
49        )))
50    } else {
51        Err(to_pyvalue_err("Expected a dictionary"))
52    }
53}
54
55/// Helper function to convert a `serde_json::Value` to a Python object.
56///
57/// This is a common conversion pattern used when converting `Params` to Python dicts.
58///
59/// # Errors
60///
61/// Returns a `PyErr` if the value type is unsupported or conversion fails.
62///
63/// # Panics
64///
65/// Panics if a numeric value claims to be `i64`/`u64`/`f64` via the predicate
66/// methods but the corresponding accessor returns `None` (should not happen for
67/// well-formed [`serde_json::Number`] values).
68pub fn value_to_pyobject(py: Python<'_>, val: &Value) -> PyResult<Py<PyAny>> {
69    match val {
70        Value::Null => Ok(py.None()),
71        Value::Bool(b) => b.into_py_any(py),
72        Value::String(s) => s.into_py_any(py),
73        Value::Number(n) => {
74            if n.is_i64() {
75                n.as_i64().unwrap().into_py_any(py)
76            } else if n.is_u64() {
77                n.as_u64().unwrap().into_py_any(py)
78            } else if n.is_f64() {
79                n.as_f64().unwrap().into_py_any(py)
80            } else {
81                Err(to_pyvalue_err("Unsupported JSON number type"))
82            }
83        }
84        Value::Array(arr) => {
85            let py_list =
86                PyList::new(py, &[] as &[Py<PyAny>]).expect("Invalid `ExactSizeIterator`");
87            for item in arr {
88                let py_item = value_to_pyobject(py, item)?;
89                py_list.append(py_item)?;
90            }
91            py_list.into_py_any(py)
92        }
93        Value::Object(_) => {
94            // For nested objects, convert to dict recursively
95            let json_str = serde_json::to_string(val).map_err(to_pyvalue_err)?;
96            let py_dict: Py<PyDict> = PyModule::import(py, "json")?
97                .call_method("loads", (json_str,), None)?
98                .extract()?;
99            py_dict.into_py_any(py)
100        }
101    }
102}
103
104/// Converts `Params` (IndexMap<String, Value>) to a Python dict.
105///
106/// # Errors
107///
108/// Returns a `PyErr` if conversion of any value fails.
109pub fn params_to_pydict(py: Python<'_>, params: &Params) -> PyResult<Py<PyDict>> {
110    let dict = PyDict::new(py);
111    for (key, value) in params {
112        let py_value = value_to_pyobject(py, value)?;
113        dict.set_item(key, py_value)?;
114    }
115    Ok(dict.into())
116}
nautilus_core/python/params.rs

nautilus_core/python/
params.rs
