add to_list api, some conversion logic

Author: zachspar

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "parquet-py"
-version = "0.0.1-alpha"
+version = "0.0.2-alpha"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
@@ -11,3 +11,4 @@ crate-type = ["cdylib"]
 [dependencies]
 parquet = { version = "52.0.0", features = ["json"] }
 pyo3 = "0.22.0"
+serde_json = "1.0.120"

Cargo.toml

@@ -1,6 +1,53 @@
 use pyo3::prelude::*;
+use pyo3::types::{PyDict, PyList, PyBool};
 use parquet::file::reader::{FileReader, SerializedFileReader};
 use std::{fs::File, path::Path};
+use serde_json::Value;
+
+struct PyValue(Value);
+
+impl ToPyObject for PyValue {
+    fn to_object(&self, py: Python) -> PyObject {
+        match value_to_py_object(py, &self.0) {
+            Ok(obj) => obj,
+            Err(_) => py.None(), // Fallback to None in case of error, adjust as needed
+        }
+    }
+}
+
+/// Converts a serde_json `Value` to a PyObject.
+fn value_to_py_object(py: Python, value: &Value) -> PyResult<PyObject> {
+    match value {
+        Value::Null => Ok(py.None()),
+        Value::Bool(b) => Ok(PyBool::new_bound(py, *b).into_py(py)), // Adjusted for PyBool
+        Value::Number(num) => {
+            if let Some(i) = num.as_i64() {
+                Ok(i.into_py(py))
+            } else if let Some(f) = num.as_f64() {
+                Ok(f.into_py(py))
+            } else {
+                Err(PyErr::new::<pyo3::exceptions::PyValueError, _>(
+                    "Unsupported number type",
+                ))
+            }
+        },
+        Value::String(s) => Ok(s.into_py(py)),
+        Value::Array(arr) => {
+            let py_list = PyList::empty_bound(py);
+            for item in arr {
+                py_list.append(value_to_py_object(py, item)?)?;
+            }
+            Ok(py_list.into_py(py))
+        },
+        Value::Object(obj) => {
+            let py_dict = PyDict::new_bound(py); // Correct usage of PyDict
+            for (k, v) in obj {
+                py_dict.set_item(k, value_to_py_object(py, v)?)?;
+            }
+            Ok(py_dict.into_py(py))
+        },
+    }
+}
 
 // convert parquet file to json string
 #[pyfunction]
@@ -21,15 +68,38 @@ fn to_json_str(path: &str) -> PyResult<String> {
 
         // return json string
         return Ok(json_str);
+    } else {
+        // return ValueError if file not found
+        Err(PyErr::new::<pyo3::exceptions::PyValueError, _>("Unable to open parquet file"))
     }
+}
 
-    // return ValueError if file not found
-    Err(PyErr::new::<pyo3::exceptions::PyValueError, _>("Unable to open parquet file"))
+#[pyfunction]
+fn to_list(path: &str, py: Python) -> PyResult<PyObject> {
+    let file_path = Path::new(path);
+    if let Ok(file) = File::open(&file_path) {
+        let reader = SerializedFileReader::new(file).unwrap();
+
+        let list = PyList::empty_bound(py);
+        for row in reader.get_row_iter(None).unwrap() {
+            let row_dict = row.unwrap().to_json_value();
+            let dict = PyDict::new_bound(py);
+            for (key, value) in row_dict.as_object().unwrap() {
+                dict.set_item(key, PyValue(value.clone()))?;
+                list.append(&dict)?;
+            }
+        }
+
+        Ok(list.into())
+    } else {
+        Err(PyErr::new::<pyo3::exceptions::PyValueError, _>("Unable to open parquet file"))
+    }
 }
 
 // python module
 #[pymodule]
 fn parq(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_function(wrap_pyfunction!(to_json_str, m)?)?;
+    m.add_function(wrap_pyfunction!(to_list, m)?)?;
     Ok(())
 }