old_contents: 
  """
  Usage::
  
      import install_pyenv
      install_pyenv.install()
  
  """
  
  import sys
  
  from subprocess import check_call
  
  
  def _log(*args):
      print(" ".join(args))
      sys.stdout.flush()
  
  
  def install(py_version):
      """Download and install ``pyenv``."""
  
      check_call(
          "\n".join((
              "brew update",
              "brew outdated pyenv || brew upgrade pyenv",
              "eval \"$( pyenv init - )\"",
              "pyenv install " + py_version,
              "pyenv local " + py_version,
              "echo 'Python Version:'",
              (
                  "python -c \""
                  "import sys, struct ; "
                  "print(sys.version) ; "
                  "print('{}-bit'.format(struct.calcsize('P') * 8))"
                  "\""
              )
          )),
          shell=True
      )
  
  
  if __name__ == '__main__':
      install()
  
new_contents: 
  """
  Usage::
  
      import install_pyenv
      install_pyenv.install("3.4.5")
  
  """
  
  import os
  import sys
  
  from subprocess import check_call
  
  
  def _log(*args):
      print(" ".join(args))
      sys.stdout.flush()
  
  
  def install(py_version):
      """Download and install ``pyenv``."""
  
      check_call(
          "\n".join((
              "brew update",
              "brew outdated pyenv || brew upgrade pyenv",
              "eval \"$( pyenv init - )\"",
              "pyenv install " + py_version,
              "pyenv local " + py_version,
              "echo 'Python Version:'",
              (
                  "python -c \""
                  "import sys, struct ; "
                  "print(sys.version) ; "
                  "print('{}-bit'.format(struct.calcsize('P') * 8))"
                  "\""
              )
          )),
          shell=True
      )
  
  
  if __name__ == '__main__':
      install(os.environ['PYTHONVERSION'])
  
subject: Fix cli execution mode getting value of PYTHONVERSION