Drop Python 2.6 compatibility? about webbpsf HOT 3 CLOSED

$ python
Python 2.6.9 |Continuum Analytics, Inc.| (unknown, Jan 10 2014, 13:33:57)
[GCC 4.2.1 (Apple Inc. build 5577)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import webbpsf
WebbPSF log messages of level INFO and above will be shown.
WebbPSF log outputs will be directed to the screen.
>>> webbpsf.Instrument('NIRCam')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/jlong/src/webbpsf/webbpsf/webbpsf_core.py", line 1288, in Instrument
    if name == 'nircam': return NIRCam()
  File "/Users/jlong/src/webbpsf/webbpsf/webbpsf_core.py", line 871, in __init__
    self.detector=self.detector_list[0]
  File "/Users/jlong/src/webbpsf/webbpsf/webbpsf_core.py", line 262, in detector
    self._detector = DetectorGeometry(self.name, siaf_aperture_name, shortname=detname)
  File "/Users/jlong/src/webbpsf/webbpsf/webbpsf_core.py", line 1343, in __init__
    self.mysiaf = SIAF(instr=self.instrname, basepath=os.path.join( utils.get_webbpsf_data_path(), self.instrname) )
  File "/Users/jlong/src/webbpsf/webbpsf/jwxml.py", line 576, in __init__
    for entry in self._tree.getroot().iter('SiafEntry'):
AttributeError: iter
>>>