add readme

src/lib.rs

@@ -1,7 +1,8 @@
 #[macro_use]
 extern crate cpython;
 
-use cpython::{PyResult, Python};
+use cpython::{PyResult, Python, PyObject};
+use cpython::buffer::PyBuffer;
 
 // Our module is named 'hello', and can be imported using `import hello`.
 // This requires that the output binary file is named `hello.so` (or Windows: `hello.pyd`).
@@ -11,6 +12,7 @@ use cpython::{PyResult, Python};
 py_module_initializer!(hello, inithello, PyInit_hello, |py, m| {
     m.add(py, "__doc__", "Module documentation string")?;
     m.add(py, "func", py_fn!(py, func(x: Vec<f64>)))?;
+    m.add(py, "funcbuff", py_fn!(py, funcbuff(x: &PyObject)))?;
     Ok(())
 });
 
@@ -22,4 +24,10 @@ py_module_initializer!(hello, inithello, PyInit_hello, |py, m| {
 // Most functions in the `cpython` crate require that you pass this argument.
 fn func(_: Python,  x: Vec<f64>) -> PyResult<f64> {
     Ok(x.into_iter().inspect(|i| println!("{:}", i)).sum())
+}
+
+fn funcbuff(py: Python,  x: &PyObject) -> PyResult<f64> {
+    let x = PyBuffer::get(py, x)?;
+    let x = x.as_slice::<f64>(py).expect("not a buffer of f64"); // fix to return err
+    Ok(x.into_iter().map(|i| i.get()).inspect(|i| println!("{:}", i)).sum())
 }

test.py

@@ -11,4 +11,5 @@
 
 x = np.arange(12.).astype('float64').reshape((-1, 2), order='c')
 print x
-print hello.func(x[:, 1])# seams to only work with 1 d arrays
+print hello.func(x[:, 1])  # seams to only work with 1 d arrays
+print hello.funcbuff(x)  # dose not work with slices