Python2 support

Author: kngwyu

Cargo.toml

@@ -16,3 +16,12 @@ num-complex = "0.2"
 num-traits = "0.2.6"
 ndarray = "0.12"
 pyo3 = "0.5.0-alpha.2"
+
+[features]
+# In default setting, python version is automatically detected
+default = []
+# Use this feature when building python2 binding.
+python2 = ["pyo3/python2"]
+# Use this feature when building python3 binding.
+python3 = ["pyo3/python3"]
+

examples/simple-extension/setup.py

@@ -14,6 +14,13 @@ def run(self):
         raise SystemExit(errno)
 
 
+def get_cfg_flags():
+    version = sys.version_info[0:2]
+    if version[0] == 2:
+        return ['--cfg=Py_2']
+    else:
+        return ['--cfg=Py_3']
+
 setup_requires = ['setuptools-rust>=0.6.0']
 install_requires = ['numpy']
 test_requires = install_requires + ['pytest']
@@ -22,7 +29,9 @@ def run(self):
     name='rust_ext',
     version='0.1.0',
     description='Example of python-extension using rust-numpy',
-    rust_extensions=[RustExtension('rust_ext.rust_ext', './Cargo.toml')],
+    rust_extensions=[RustExtension(
+        'rust_ext.rust_ext', './Cargo.toml', rustc_flags=get_cfg_flags()
+    )],
     install_requires=install_requires,
     setup_requires=setup_requires,
     test_requires=test_requires,

examples/simple-extension/tests/test_ext.py

@@ -7,8 +7,8 @@ def test_axpy():
     y = np.array([3.0, 3.0, 3.0])
     z = axpy(3.0, x, y)
     np.testing.assert_array_almost_equal(z, np.array([6.0, 9.0, 12.0]))
-    x = np.array([*x, 4.0])
-    y = np.array([*y, 3.0])
+    x = np.array([1.0, 2.0, 3.0, 4.0])
+    y = np.array([3.0, 3.0, 3.0, 3.0])
     z = axpy(3.0, x, y)
     np.testing.assert_array_almost_equal(z, np.array([6.0, 9.0, 12.0, 15.0]))
 

examples/simple-extension/tox.ini

@@ -1,5 +1,6 @@
 [tox]
-envlist = py35,
+envlist = py27,
+          py35,
           py36,
           py37,
 minversion = 2.9.0

src/npyffi/mod.rs

@@ -12,11 +12,19 @@
 use pyo3::ffi;
 use std::ffi::CString;
 use std::os::raw::c_void;
-use std::ptr::null_mut;
 
 fn get_numpy_api(module: &str, capsule: &str) -> *const *const c_void {
     let module = CString::new(module).unwrap();
     let capsule = CString::new(capsule).unwrap();
+    #[cfg(not(Py_3))]
+    unsafe fn get_capsule(capsule: *mut ffi::PyObject) -> *const *const c_void {
+        ffi::PyCObject_AsVoidPtr(capsule) as *const *const c_void
+    }
+    #[cfg(Py_3)]
+    unsafe fn get_capsule(capsule: *mut ffi::PyObject) -> *const *const c_void {
+        use std::ptr::null_mut;
+        ffi::PyCapsule_GetPointer(capsule, null_mut()) as *const *const c_void
+    }
     unsafe {
         assert_ne!(
             ffi::Py_IsInitialized(),
@@ -27,7 +35,8 @@ Please make sure that you get gil, by `let gil = Python::acquire_gil();`"
         let numpy = ffi::PyImport_ImportModule(module.as_ptr());
         assert!(!numpy.is_null(), "Failed to import numpy module");
         let capsule = ffi::PyObject_GetAttrString(numpy as *mut ffi::PyObject, capsule.as_ptr());
-        ffi::PyCapsule_GetPointer(capsule, null_mut()) as *const *const c_void
+        assert!(!capsule.is_null(), "Failed to import numpy module");
+        get_capsule(capsule)
     }
 }