Please help me error "AttributeError: 'module' object has no attribute 'ElementTree'"

[mattroi261192]

Hi everyone,
I have trouble when I code python as below.
I have a simple code:

import xlrd
file_location = "D:\Training\Python\Email\aa.xlsx"
workbook = xlrd.open_workbook(file_location)
sheet = workbook.sheet_by_index(0)
print sheet

After I run the program, it shows error:

Error:
    workbook = xlrd.open_workbook(file_location)
  File "C:\Python27\lib\site-packages\xlrd-1.0.0-py2.7.egg\xlrd\__init__.py", li
ne 422, in open_workbook
    ragged_rows=ragged_rows,
  File "C:\Python27\lib\site-packages\xlrd-1.0.0-py2.7.egg\xlrd\xlsx.py", line 7
84, in open_workbook_2007_xml
    ensure_elementtree_imported(verbosity, logfile)
  File "C:\Python27\lib\site-packages\xlrd-1.0.0-py2.7.egg\xlrd\xlsx.py", line 5
2, in ensure_elementtree_imported
    Element_has_iter = hasattr(ET.ElementTree, 'iter')
AttributeError: 'module' object has no attribute 'ElementTree'

I tried installing xlrd 1.10 (latest version)and xlrd 1.0.0 version. Please help me to fix this problem. Thank all.