Halstead Metrics not able to compute

[shiva10162]

I am trying to include halstead module by using pymetrics -i halstead:HalsteadMetric <FileName> but it gives me error :

Traceback (most recent call last):

 File "/home/user/.local/bin/pymetrics", line 6, in <module>
    pm.main ()
  File "/home/user/.local/lib/python2.7/site-packages/PyMetrics/PyMetrics.py", line 194, in main
    metrics = cm( lex )
  File "/home/user/.local/lib/python2.7/site-packages/PyMetrics/compute.py", line 198, in __call__
    tokCount = self.handleToken( tokCount, tok )
  File "/home/user/.local/lib/python2.7/site-packages/PyMetrics/compute.py", line 372, in handleToken
    self.processModule()
  File "/home/user/.local/lib/python2.7/site-packages/PyMetrics/compute.py", line 155, in processModule
    subscriber.processModule( moduleName, mod )
  File "/home/user/.local/lib/python2.7/site-packages/PyMetrics/halstead.py", line 120, in processModule
    result = self.computeCategory( 'module', moduleName, mod )
  File "/home/user/.local/lib/python2.7/site-packages/PyMetrics/halstead.py", line 156, in computeCategory
    for tok in lst:
TypeError: 'ComputeMetrics' object is not iterable 

Not sure what's the problem. Can anyone please look into this?