preliminary python function and test

Author: flexatone

Cargo.lock

@@ -10,3 +10,4 @@ crate-type = ["cdylib"]
 
 [dependencies]
 pyo3 = "0.25.0"
+numpy = "0.25.0"

Cargo.toml

@@ -1,14 +1,17 @@
 use pyo3::prelude::*;
+use numpy::PyReadonlyArray1;
 
-/// Formats the sum of two numbers as string.
 #[pyfunction]
-fn sum_as_string(a: usize, b: usize) -> PyResult<String> {
-    Ok((a + b).to_string())
+fn first_true_1d(array: PyReadonlyArray1<bool>) -> isize {
+    match array.as_slice() {
+        Ok(slice) => slice.iter().position(|&v| v).map(|i| i as isize).unwrap_or(-1),
+        Err(_) => -1, // Should not happen for 1D arrays, but fallback to -1
+    }
 }
 
-/// A Python module implemented in Rust.
+
 #[pymodule]
 fn arrayredox(m: &Bound<'_, PyModule>) -> PyResult<()> {
-    m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
+    m.add_function(wrap_pyfunction!(first_true_1d, m)?)?;
     Ok(())
 }

src/lib.rs

@@ -0,0 +1,13 @@
+from arrayredox import first_true_1d
+import numpy as np
+
+def test_first_true_1d():
+
+    a = np.array([False, False, True, False])
+    assert first_true_1d(a) == 2
+
+    b = np.array([False, False, False])
+    assert first_true_1d(b) == -1
+
+
+