code: def env(lang="python3.6"):
      if VENV_DIR.exists():
          local("rm -rf {env}".format(env=VENV_DIR))
      if lang.startswith("python3"):
          local("{lang} -m venv {env}".format(lang=lang, env=VENV_DIR))
      else:
          local(
              "{lang} -m pip install virtualenv --no-cache-dir".format(
                  lang=lang
              )
          )
          local(
              "{lang} -m virtualenv {env} --no-cache-dir".format(
                  lang=lang, env=VENV_DIR
              )
          )
      with virtualenv(VENV_DIR) as venv_local:
          print(venv_local("python --version", capture=True))
          venv_local("pip install --upgrade setuptools --no-cache-dir")
          venv_local("pip install pytest --no-cache-dir")
          venv_local("pip install wheel --no-cache-dir")
          venv_local("pip install -r requirements.txt --no-cache-dir")
          venv_local("pip install pex --no-cache-dir")
  
file_path: cython-blis/fabfile.py
imports: from __future__ import unicode_literals, print_function
  import contextlib
  from pathlib import Path
  from fabric.api import local, lcd, env, settings, prefix
  from os import path, environ
  import shutil
  import sys
label_desc: Use image node_id 2 for calling a global function with example usage: env(lang) without return types