feat(ws): support DECIMAL data type (#388)

Author: qevolg

.github/workflows/taos-ws-py-enterprise.yml

@@ -85,13 +85,13 @@ jobs:
         run: pip install taos-ws-py --no-index --force-reinstall --find-links taos-ws-py/target/wheels
 
       - name: Get TDengine
-        run: wget "${{ secrets.NIGHTLY_TDENGINE_ENTERPRISE_BASE_URL }}/tsdb-nightly-3.0.tar.gz?v=$(date +%s)" -O tsdb-nightly-3.0.tar.gz
+        run: wget "${{ secrets.NIGHTLY_TDENGINE_ENTERPRISE_BASE_URL }}/tsdb-nightly-main.tar.gz?v=$(date +%s)" -O tsdb-nightly-main.tar.gz
 
       - name: Install TDengine
         run: |
-          tar -zxf tsdb-nightly-3.0.tar.gz
-          rm -rf tsdb-nightly-3.0.tar.gz
-          cd tsdb-nightly-3.0
+          tar -zxf tsdb-nightly-main.tar.gz
+          rm -rf tsdb-nightly-main.tar.gz
+          cd tsdb-nightly-main
           sudo ./install.sh
 
       - name: Copy taos.cfg

taos-ws-py/CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Conventional Changelog](https://www.conventionalcommits.org/en/v1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## v0.6.8 - 2026-04-09
+
+### Features:
+
+- Support DECIMAL data type
+
 ## v0.6.7 - 2026-03-31
 
 ### Enhancements:

taos-ws-py/Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "taos-ws-py"
-version = "0.6.7"
+version = "0.6.8"
 edition = "2021"
 publish = false
 license = "MIT"
@@ -11,6 +11,7 @@ crate-type = ["cdylib"]
 
 [dependencies]
 anyhow = "1"
+bigdecimal = "0.4"
 chrono = "0.4"
 chrono-tz = "0.10.4"
 iana-time-zone = "0.1.63"

taos-ws-py/Cargo.toml

@@ -11,6 +11,13 @@ use taos::{taos_query::common::Timestamp, BorrowedValue, RawBlock};
 
 use crate::ConsumerException;
 
+pub fn to_py_decimal(value: impl std::fmt::Display, py: Python<'_>) -> PyResult<PyObject> {
+    let decimal_mod = py.import("decimal")?;
+    let decimal_cls = decimal_mod.getattr("Decimal")?;
+    let decimal = value.to_string();
+    Ok(decimal_cls.call1((decimal,))?.into_py(py))
+}
+
 pub fn to_py_datetime(ts: Timestamp, tz: Option<Tz>, py: Python) -> PyResult<PyObject> {
     let datetime_mod = py.import("datetime")?;
     let datetime = datetime_mod.getattr("datetime")?;
@@ -94,7 +101,11 @@ fn warn_missing_timezone_libs(tz: Option<Tz>) {
     });
 }
 
-pub unsafe fn get_row_of_block_unchecked(py: Python, block: &RawBlock, index: usize) -> PyObject {
+pub unsafe fn get_row_of_block_unchecked(
+    py: Python,
+    block: &RawBlock,
+    index: usize,
+) -> PyResult<PyObject> {
     let mut vec = Vec::new();
     for i in 0..block.ncols() {
         let val = block.get_ref(index, i).unwrap();
@@ -110,43 +121,44 @@ pub unsafe fn get_row_of_block_unchecked(py: Python, block: &RawBlock, index: us
             BorrowedValue::VarChar(v) => v.into_py(py),
             BorrowedValue::Timestamp(v) => match v.precision() {
                 taos::Precision::Nanosecond => v.as_raw_i64().to_object(py),
-                _ => to_py_datetime(v, block.timezone(), py).unwrap(),
+                _ => to_py_datetime(v, block.timezone(), py)?,
             },
             BorrowedValue::NChar(v) => v.into_py(py),
             BorrowedValue::UTinyInt(v) => v.into_py(py),
             BorrowedValue::USmallInt(v) => v.into_py(py),
             BorrowedValue::UInt(v) => v.into_py(py),
             BorrowedValue::UBigInt(v) => v.into_py(py),
             BorrowedValue::Json(v) => std::str::from_utf8(&v)
-                .map_err(|err| ConsumerException::new_err(err.to_string()))
-                .unwrap()
+                .map_err(|err| ConsumerException::new_err(err.to_string()))?
                 .to_string()
                 .into_py(py),
             BorrowedValue::VarBinary(v) => v.into_py(py),
             BorrowedValue::Geometry(v) => v.into_py(py),
-            BorrowedValue::Decimal64(v) => v.to_string().into_py(py),
-            BorrowedValue::Decimal(v) => v.to_string().into_py(py),
+            BorrowedValue::Decimal64(v) => to_py_decimal(v, py)?,
+            BorrowedValue::Decimal(v) => to_py_decimal(v, py)?,
             BorrowedValue::Blob(v) => v.into_py(py),
             BorrowedValue::MediumBlob(_) => todo!(),
         };
         vec.push(val);
     }
-    PyTuple::new(py, vec).to_object(py)
+    Ok(PyTuple::new(py, vec).to_object(py))
 }
 
-pub fn get_row_of_block(py: Python, block: &RawBlock, index: usize) -> Option<PyObject> {
+pub fn get_row_of_block(py: Python, block: &RawBlock, index: usize) -> PyResult<Option<PyObject>> {
     if block.nrows() > index {
-        Some(unsafe { get_row_of_block_unchecked(py, block, index) })
+        Ok(Some(unsafe {
+            get_row_of_block_unchecked(py, block, index)?
+        }))
     } else {
-        None
+        Ok(None)
     }
 }
 
 pub fn get_slice_of_block(
     py: Python,
     block: &RawBlock,
     range: Range<usize>,
-) -> (Vec<PyObject>, Option<usize>) {
+) -> PyResult<(Vec<PyObject>, Option<usize>)> {
     debug_assert!(range.start < block.nrows());
     let start = range.start;
     let end = range.end;
@@ -159,14 +171,14 @@ pub fn get_slice_of_block(
     let slices = range
         .into_iter()
         .map(|index| unsafe { get_row_of_block_unchecked(py, block, index) })
-        .collect();
+        .collect::<PyResult<Vec<_>>>()?;
 
-    (slices, remain)
+    Ok((slices, remain))
 }
 
-pub fn get_all_of_block(py: Python, block: &RawBlock) -> Vec<PyObject> {
+pub fn get_all_of_block(py: Python, block: &RawBlock) -> PyResult<Vec<PyObject>> {
     (0..block.nrows())
         .into_iter()
         .map(|index| unsafe { get_row_of_block_unchecked(py, block, index) })
-        .collect()
+        .collect::<PyResult<Vec<_>>>()
 }

taos-ws-py/src/common.rs

@@ -354,7 +354,7 @@ impl MessageBlock {
         self.block.ncols()
     }
 
-    pub fn fetchall(&self) -> Vec<PyObject> {
+    pub fn fetchall(&self) -> PyResult<Vec<PyObject>> {
         Python::with_gil(|py| get_all_of_block(py, &self.block))
     }
 
@@ -379,7 +379,7 @@ impl MessageBlockIter {
             Ok(None)
         } else {
             Python::with_gil(|py| {
-                let values = unsafe { get_row_of_block_unchecked(py, &slf.block, slf.index) };
+                let values = unsafe { get_row_of_block_unchecked(py, &slf.block, slf.index)? };
                 slf.index += 1;
                 Ok(Some(values))
             })

taos-ws-py/src/consumer.rs

@@ -279,14 +279,14 @@ impl Cursor {
     pub fn fetchone(&mut self) -> PyResult<Option<PyObject>> {
         self.assert_block()?;
 
-        Ok(Python::with_gil(|py| -> Option<PyObject> {
+        Python::with_gil(|py| -> PyResult<Option<PyObject>> {
             if let Some(block) = self.block.as_ref() {
-                let row = get_row_of_block(py, block, self.row_in_block).unwrap();
+                let row = get_row_of_block(py, block, self.row_in_block)?;
                 self.row_in_block += 1;
-                return Some(row);
+                return Ok(row);
             }
-            None
-        }))
+            Ok(None)
+        })
     }
 
     /// PEP249 void method
@@ -299,7 +299,7 @@ impl Cursor {
                 let mut all = Vec::new();
                 loop {
                     if let Some(block) = self.block.take() {
-                        let (slice, remain) = get_slice_of_block(py, &block, range.clone());
+                        let (slice, remain) = get_slice_of_block(py, &block, range.clone())?;
                         all.extend(slice);
                         if remain.is_none() {
                             self.block = Some(block);
@@ -323,7 +323,7 @@ impl Cursor {
             self.row_in_block = 0;
             if let Some(block) = self.block.take() {
                 self.row_count += block.nrows();
-                return Ok(Some(Python::with_gil(|py| get_all_of_block(py, &block))));
+                return Ok(Some(Python::with_gil(|py| get_all_of_block(py, &block))?));
             } else {
                 return Ok(None);
             }