Function buildPythonEnv

packages/runtime-core/src/python-env.ts:181–210

(
  resolvedPythonPath: string,
  baseEnv: Record<string, string | undefined> = process.env
)

 * @returns Environment variables object for use with child_process.spawn()
 */
export async function buildPythonEnv(
  resolvedPythonPath: string,
  baseEnv: Record<string, string | undefined> = process.env
): Promise<Record<string, string | undefined>> {
  const env = { ...baseEnv }

  if (isBareSystemPython(resolvedPythonPath)) {
    return env
  }

  const pythonDir = dirname(resolve(resolvedPythonPath))

  // Prepend the Python's directory to PATH so subprocesses (e.g. Jupyter kernels)
  // find the correct Python when using bare 'python' commands
  const pathKey = Object.keys(env).find(k => k.toLowerCase() === 'path') || 'PATH'
  const currentPath = env[pathKey] || ''
  env[pathKey] = currentPath ? `${pythonDir}${delimiter}${currentPath}` : pythonDir

  // Detect if this Python is inside a virtual environment
  const venvRoot = await detectVenvRoot(resolve(resolvedPythonPath))
  if (venvRoot) {
    env.VIRTUAL_ENV = venvRoot
  } else {
    // Clear any inherited VIRTUAL_ENV to prevent the current shell's venv
    // from interfering with the specified Python
    delete env.VIRTUAL_ENV
  }

  return env
}