互通三件套

rust側與python互通的三個庫：

pyo3

pythonize

serde

pyo3

pyo3跟用Python C API寫python擴展有點類似，核心是：

#[pymodule]
#[pyfunction]

兩個注解。前者對應Py_InitModule，后者對應PyMethodDef。

下面是其它博客上一個python C API寫擴展的例子：

//Python.h has all the required function definitions to manipulate the Python objects
#include <Python.h>//This is the function that is called from your python code
static PyObject* addList_add(PyObject* self, PyObject* args){PyObject * listObj;//The input arguments come as a tuple, we parse the args to get the various variables//In this case it's only one list variable, which will now be referenced by listObjif (! PyArg_ParseTuple( args, "O", &listObj ))return NULL;//length of the listlong length = PyList_Size(listObj);//iterate over all the elementsint i, sum =0;for (i = 0; i < length; i++) {//get an element out of the list - the element is also a python objectsPyObject* temp = PyList_GetItem(listObj, i);//we know that object represents an integer - so convert it into C longlong elem = PyInt_AsLong(temp);sum += elem;}//value returned back to python code - another python object//build value here converts the C long to a python integerreturn Py_BuildValue("i", sum);}//This is the docstring that corresponds to our 'add' function.
static char addList_docs[] =
"add(  ): add all elements of the list\n";/* This table contains the relavent info mapping -<function-name in python module>, <actual-function>,<type-of-args the function expects>, <docstring associated with the function>*/
static PyMethodDef addList_funcs[] = {{"add", (PyCFunction)addList_add, METH_VARARGS, addList_docs},{NULL, NULL, 0, NULL}};/*addList is the module name, and this is the initialization block of the module.<desired module name>, <the-info-table>, <module's-docstring>*/
PyMODINIT_FUNC initaddList(void){Py_InitModule3("addList", addList_funcs,"Add all ze lists");}

下面是截取的開源庫sqloxide的樣例代碼：

#[pyfunction]
#[pyo3(text_signature = "(sql, dialect)")]
fn parse_sql(py: Python, sql: String, dialect: String) -> PyResult<PyObject> {let chosen_dialect = dialect_from_str(dialect).unwrap_or_else(|| {println!("The dialect you chose was not recognized, falling back to 'generic'");Box::new(GenericDialect {})});let parse_result = Parser::parse_sql(&*chosen_dialect, &sql);...Ok(output.into())
}#[pymodule]
fn sqloxide(_py: Python, m: &Bound<'_, PyModule>) -> PyResult<()> {m.add_function(wrap_pyfunction!(parse_sql, m)?)?;m.add_function(wrap_pyfunction!(restore_ast, m)?)?;...Ok(())
}

pythonize

pythonnize完成rust數據結構到python數據結構的互轉。本質上是一個序列化/反序列化器。序列化的結果是一個json結構，可用常見的json庫解析。