polars_python/functions/
io.rs

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1use std::io::BufReader;
2
3use arrow::array::Utf8ViewArray;
4#[cfg(any(feature = "ipc", feature = "parquet"))]
5use polars::prelude::ArrowSchema;
6use polars_core::datatypes::create_enum_dtype;
7use pyo3::prelude::*;
8use pyo3::types::PyDict;
9
10use crate::conversion::Wrap;
11use crate::error::PyPolarsErr;
12use crate::file::{get_either_file, EitherRustPythonFile};
13use crate::prelude::ArrowDataType;
14
15#[cfg(feature = "ipc")]
16#[pyfunction]
17pub fn read_ipc_schema(py: Python, py_f: PyObject) -> PyResult<Bound<PyDict>> {
18    use arrow::io::ipc::read::read_file_metadata;
19    let metadata = match get_either_file(py_f, false)? {
20        EitherRustPythonFile::Rust(r) => {
21            read_file_metadata(&mut BufReader::new(r)).map_err(PyPolarsErr::from)?
22        },
23        EitherRustPythonFile::Py(mut r) => read_file_metadata(&mut r).map_err(PyPolarsErr::from)?,
24    };
25
26    let dict = PyDict::new(py);
27    fields_to_pydict(&metadata.schema, &dict)?;
28    Ok(dict)
29}
30
31#[cfg(feature = "parquet")]
32#[pyfunction]
33pub fn read_parquet_schema(py: Python, py_f: PyObject) -> PyResult<Bound<PyDict>> {
34    use polars_parquet::read::{infer_schema, read_metadata};
35
36    let metadata = match get_either_file(py_f, false)? {
37        EitherRustPythonFile::Rust(r) => {
38            read_metadata(&mut BufReader::new(r)).map_err(PyPolarsErr::from)?
39        },
40        EitherRustPythonFile::Py(mut r) => read_metadata(&mut r).map_err(PyPolarsErr::from)?,
41    };
42    let arrow_schema = infer_schema(&metadata).map_err(PyPolarsErr::from)?;
43
44    let dict = PyDict::new(py);
45    fields_to_pydict(&arrow_schema, &dict)?;
46    Ok(dict)
47}
48
49#[cfg(any(feature = "ipc", feature = "parquet"))]
50fn fields_to_pydict(schema: &ArrowSchema, dict: &Bound<'_, PyDict>) -> PyResult<()> {
51    for field in schema.iter_values() {
52        let dt = if field.is_enum() {
53            Wrap(create_enum_dtype(Utf8ViewArray::new_empty(
54                ArrowDataType::Utf8View,
55            )))
56        } else {
57            Wrap(polars::prelude::DataType::from_arrow_field(field))
58        };
59        dict.set_item(field.name.as_str(), &dt)?;
60    }
61    Ok(())
62}
63
64#[cfg(feature = "clipboard")]
65#[pyfunction]
66pub fn read_clipboard_string() -> PyResult<String> {
67    use arboard;
68    let mut clipboard =
69        arboard::Clipboard::new().map_err(|e| PyPolarsErr::Other(format!("{e}")))?;
70    let result = clipboard
71        .get_text()
72        .map_err(|e| PyPolarsErr::Other(format!("{e}")))?;
73    Ok(result)
74}
75
76#[cfg(feature = "clipboard")]
77#[pyfunction]
78pub fn write_clipboard_string(s: &str) -> PyResult<()> {
79    use arboard;
80    let mut clipboard =
81        arboard::Clipboard::new().map_err(|e| PyPolarsErr::Other(format!("{e}")))?;
82    clipboard
83        .set_text(s)
84        .map_err(|e| PyPolarsErr::Other(format!("{e}")))?;
85    Ok(())
86}
polars_python/functions/io.rs

polars_python/functions/
io.rs
