docs: def shell_source(script):
      """Sometime you want to emulate the action of "source" in bash,
      settings some environment variables. Here is a way to do it."""
      pipe = subprocess.Popen(
          ". %s; env" % script, stdout=subprocess.PIPE, shell=True)
      output = pipe.communicate()[0].decode()
      env = {}
      for line in output.splitlines():
          try:
              keyval = line.split("=", 1)
              env[keyval[0]] = keyval[1]
          except:
              pass
  
      os.environ.update(env)