Function runPython

src/python/pythonUtils.ts:302–395

(
  scriptPath: string,
  method: string,
  args: (string | number | object | undefined)[],
  options: { pythonExecutable?: string } = {},
)

 * @throws An error if there's an issue running the Python script or parsing its output.
 */
export async function runPython<T = unknown>(
  scriptPath: string,
  method: string,
  args: (string | number | object | undefined)[],
  options: { pythonExecutable?: string } = {},
): Promise<T> {
  const absPath = path.resolve(scriptPath);
  const customPath = getConfiguredPythonPath(options.pythonExecutable);
  let pythonPath = customPath || 'python';
  let tempDirectory: string | undefined;

  pythonPath = await validatePythonPath(pythonPath, typeof customPath === 'string');

  try {
    tempDirectory = await createSecureTempDirectory('promptfoo-python-');
    const tempJsonPath = await writeSecureTempFile(
      tempDirectory,
      'input.json',
      safeJsonStringify(args) as string,
    );
    const outputPath = await writeSecureTempFile(tempDirectory, 'output.json', '');
    const pythonOptions: PythonShellOptions = {
      args: [absPath, method, tempJsonPath, outputPath],
      env: process.env,
      mode: 'binary',
      pythonPath,
      scriptPath: getWrapperDir('python'),
      // When `inherit` is used, `import pdb; pdb.set_trace()` will work.
      ...(getEnvBool('PROMPTFOO_PYTHON_DEBUG_ENABLED') && { stdio: 'inherit' }),
    };

    logger.debug('[Python] Running script', { scriptPath: absPath, method });

    await new Promise<void>((resolve, reject) => {
      try {
        const pyshell = new PythonShell('wrapper.py', pythonOptions);
        const stderrLogger = new PythonStderrLogger();

        pyshell.stdout?.on('data', (chunk: Buffer) => {
          logger.debug(chunk.toString('utf-8').trim());
        });

        pyshell.stderr?.on('data', (chunk: Buffer) => {
          stderrLogger.handleData(chunk);
        });

        pyshell.end((err) => {
          stderrLogger.flush();
          if (err) {
            reject(err);
          } else {
            resolve();
          }
        });
      } catch (error) {
        reject(error);
      }
    });