sum function

[Mike]

I agree with you, Ian. Thanks for all the help.  Now I get the below error.

  File "test.py", line 17, in <module>
    total = sum(float(col.value) for r in iter(next_r, None) for col in r[0].columns.itervalues())
  File "test.py", line 17, in <genexpr>
    total = sum(float(col.value) for r in iter(next_r, None) for col in r[0].columns.itervalues())

Thanks