numpy 0.3.2

Rust binding of NumPy C-API
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163

rust-numpy
===========
[![Build Status](https://travis-ci.org/rust-numpy/rust-numpy.svg?branch=master)](https://travis-ci.org/rust-numpy/rust-numpy)
[![Build status](https://ci.appveyor.com/api/projects/status/bjaru43c7t1alx2x/branch/master?svg=true)](https://ci.appveyor.com/project/kngwyu/rust-numpy/branch/master)
[![Crate](http://meritbadge.herokuapp.com/numpy)](https://crates.io/crates/numpy)

Rust bindings for the NumPy C-API

API documentation
-------------
- [Latest release (possibly broken)](https://docs.rs/numpy)
- [Current Master](https://rust-numpy.github.io/rust-numpy)


Requirements
-------------
- current nightly rust (see https://github.com/PyO3/pyo3/issues/5 for nightly features, and
https://github.com/PyO3/pyo3/blob/master/build.rs for minimum required version)
- some rust libraries
  - [ndarray](https://github.com/bluss/ndarray) for rust-side matrix library
  - [pyo3](https://github.com/PyO3/pyo3) for cpython binding
  - and more (see [Cargo.toml](Cargo.toml))
- [numpy](http://www.numpy.org/) installed in your python environments (e.g., via `pip install numpy`)

**Note**
Starting from 0.3, rust-numpy migrated from rust-cpython to pyo3.
If you want to use rust-cpython, use version 0.2.1 from crates.io.


Example
---------


## Execute a Python program from Rust and get results

``` toml
[package]
name = "numpy-test"

[dependencies]
pyo3 = "^0.4.1"
numpy = "0.3"
```

``` rust
extern crate numpy;
extern crate pyo3;
use numpy::{IntoPyResult, PyArray, PyArrayModule};
use pyo3::prelude::{ObjectProtocol, PyDict, PyResult, Python};

fn main() -> Result<(), ()> {
    let gil = Python::acquire_gil();
    main_(gil.python()).map_err(|e| {
        eprintln!("error! :{:?}", e);
        // we can't display python error type via ::std::fmt::Display
        // so print error here manually
        e.print_and_set_sys_last_vars(gil.python());
    })
}

fn main_<'py>(py: Python<'py>) -> PyResult<()> {
    let np = PyArrayModule::import(py)?;
    let dict = PyDict::new(py);
    dict.set_item("np", np.as_pymodule())?;
    let pyarray: &PyArray<i32> = py
        .eval("np.array([1, 2, 3], dtype='int32')", Some(&dict), None)?
        .extract()?;
    let slice = pyarray.as_slice().into_pyresult("Array Cast failed")?;
    assert_eq!(slice, &[1, 2, 3]);
    Ok(())
}
```

## Write a Python module in Rust

Please see the [example](example) directory for a complete example

```toml
[lib]
name = "rust_ext"
crate-type = ["cdylib"]

[dependencies]
numpy = "0.3"
ndarray = "0.11"

[dependencies.pyo3]
version = "^0.4.1"
features = ["extension-module"]
```

```rust
extern crate ndarray;
extern crate numpy;
extern crate pyo3;

use ndarray::{ArrayD, ArrayViewD, ArrayViewMutD};
use numpy::{IntoPyArray, IntoPyResult, PyArray, PyArrayModule};
use pyo3::prelude::{pymodinit, PyModule, PyResult, Python};

#[pymodinit]
fn rust_ext(py: Python, m: &PyModule) -> PyResult<()> {
    // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    // You **must** write this statement for the PyArray type checker to work correctly
    // !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    let _np = PyArrayModule::import(py)?;

    // immutable example
    fn axpy(a: f64, x: ArrayViewD<f64>, y: ArrayViewD<f64>) -> ArrayD<f64> {
        a * &x + &y
    }

    // mutable example (no return)
    fn mult(a: f64, mut x: ArrayViewMutD<f64>) {
        x *= a;
    }

    // wrapper of `axpy`
    #[pyfn(m, "axpy")]
    fn axpy_py(py: Python, a: f64, x: &PyArray<f64>, y: &PyArray<f64>) -> PyResult<PyArray<f64>> {
        let np = PyArrayModule::import(py)?;
        let x = x.as_array().into_pyresult("x must be f64 array")?;
        let y = y.as_array().into_pyresult("y must be f64 array")?;
        Ok(axpy(a, x, y).into_pyarray(py, &np))
    }

    // wrapper of `mult`
    #[pyfn(m, "mult")]
    fn mult_py(_py: Python, a: f64, x: &PyArray<f64>) -> PyResult<()> {
        let x = x.as_array_mut().into_pyresult("x must be f64 array")?;
        mult(a, x);
        Ok(())
    }

    Ok(())
}
```

Contribution
-------------
This project is still in pre-alpha.
We need your feedback. Don't hesitate to open [issues](https://github.com/termoshtt/rust-numpy/issues)!

Version
--------
- v0.3.0
  - Breaking Change: Migrated to pyo3 from rust-cpython
  - Some api addition
  - [Static type checking with PhantomData](https://github.com/rust-numpy/rust-numpy/pull/41)

- v0.2.1
  - NEW: trait `IntoPyErr`, `IntoPyResult` for error translation

- v0.2.0
  - NEW: traits `IntoPyArray`, `ToPyArray`
  - MOD: Interface of `PyArray` creation functions are changed

- v0.1.1
  - Update documents

- v0.1.0
  - First Release
  - Expose unsafe interfase of Array and UFunc API