eventlet/eventlet/support/greenlets.py

   1 import distutils.version
   2
   3 try:
   4     import greenlet
   5     getcurrent = greenlet.greenlet.getcurrent
   6     GreenletExit = greenlet.greenlet.GreenletExit
   7     preserves_excinfo = (distutils.version.LooseVersion(greenlet.__version__)
   8                          >= distutils.version.LooseVersion('0.3.2'))
   9     greenlet = greenlet.greenlet
  10 except ImportError as e:
  11     raise
  12     try:
  13         from py.magic import greenlet
  14         getcurrent = greenlet.getcurrent
  15         GreenletExit = greenlet.GreenletExit
  16         preserves_excinfo = False
  17     except ImportError:
  18         try:
  19             from stackless import greenlet
  20             getcurrent = greenlet.getcurrent
  21             GreenletExit = greenlet.GreenletExit
  22             preserves_excinfo = False
  23         except ImportError:
  24             try:
  25                 from support.stacklesss import greenlet, getcurrent, GreenletExit
  26                 preserves_excinfo = False
  27                 (greenlet, getcurrent, GreenletExit)  # silence pyflakes
  28             except ImportError as e:
  29                 raise ImportError("Unable to find an implementation of greenlet.")