text: # -*- coding: utf-8 -*-
  """Activate venv for current interpreter:
  
  Use `from vtk.web import venv` along one of the following
   - `--venv /path/to/venv/base` argument
   - environment variable `VTK_VENV=/path/to/venv/base`
  
  This can be used when you must use an existing Python interpreter, not the venv bin/python.
  """
  import os
  import site
  import sys
  
  VENV_BASE = None
  VENV_LOADED = False
  
  if "--venv" in sys.argv:
      VENV_BASE = os.path.abspath(sys.argv[sys.argv.index("--venv") + 1])
  
  if os.environ.get("VTK_VENV"):
      VENV_BASE = os.path.abspath(os.environ.get("VTK_VENV"))
  
  if not VENV_LOADED and VENV_BASE and os.path.exists(VENV_BASE):
      VENV_LOADED = True
      # Code inspired by virutal-env::bin/active_this.py
      bin_dir = os.path.join(VENV_BASE, "bin")
      os.environ["PATH"] = os.pathsep.join([bin_dir] + os.environ.get("PATH", "").split(os.pathsep))
      os.environ["VIRTUAL_ENV"] = VENV_BASE
      prev_length = len(sys.path)
      python_libs = os.path.join(VENV_BASE, f"lib/python{sys.version_info.major}.{sys.version_info.minor}/site-packages")
      site.addsitedir(python_libs)
      sys.path[:] = sys.path[prev_length:] + sys.path[0:prev_length]
      sys.real_prefix = sys.prefix
      sys.prefix = VENV_BASE
      #
      print(f"VTK is using venv: {VENV_BASE}")
  