code: def prepare_virtualenv(
      venv_directory: str,
      python_bin: str,
      system_site_packages: bool,
      requirements: list[str] | None = None,
      requirements_file_path: str | None = None,
      pip_install_options: list[str] | None = None,
      index_urls: list[str] | None = None,
  ) -> str:
      """
      Create a virtual environment and install the additional python packages.
  
      :param venv_directory: The path for directory where the environment will be created.
      :param python_bin: Path to the Python executable.
      :param system_site_packages: Whether to include system_site_packages in your virtualenv.
          See virtualenv documentation for more information.
      :param requirements: List of additional python packages.
      :param requirements_file_path: Path to the ``requirements.txt`` file.
      :param pip_install_options: a list of pip install options when installing requirements
          See 'pip install -h' for available options
      :param index_urls: an optional list of index urls to load Python packages from.
          If not provided the system pip conf will be used to source packages from.
      :return: Path to a binary file with Python in a virtual environment.
      """
      if pip_install_options is None:
          pip_install_options = []
  
      if index_urls is not None:
          _generate_pip_conf(
              Path(venv_directory) / "pip.conf", index_urls
          )
  
      virtualenv_cmd = _generate_virtualenv_cmd(
          venv_directory, python_bin, system_site_packages
      )
      execute_in_subprocess(virtualenv_cmd)
  
      if (
          requirements is not None
          and requirements_file_path is not None
      ):
          raise Exception(
              "Either requirements OR requirements_file_path has to be passed, but not both"
          )
  
      pip_cmd = None
      if requirements is not None and len(requirements) != 0:
          pip_cmd = _generate_pip_install_cmd_from_list(
              venv_directory, requirements, pip_install_options
          )
      if requirements_file_path is not None and requirements_file_path:
          pip_cmd = _generate_pip_install_cmd_from_file(
              venv_directory,
              requirements_file_path,
              pip_install_options,
          )
  
      if pip_cmd:
          execute_in_subprocess(pip_cmd)
  
      return f"{venv_directory}/bin/python"
  
file_path: airflow/airflow/utils/python_virtualenv.py
imports: from __future__ import annotations
  import os
  import sys
  import warnings
  from pathlib import Path
  import jinja2
  from jinja2 import select_autoescape
  from airflow.utils.decorators import remove_task_decorator
  from airflow.utils.process_utils import execute_in_subprocess
label_desc: Use image node_id 6 for calling a global function with example usage: prepare_virtualenv(venv_directory, python_bin, system_site_packages, requirements, requirements_file_path, pip_install_options, index_urls) and returns: venv_directory, str