Use xlrd to read the file as given below. I have done it in odoo9. You may try this.

from xlrd import open_workbook
import base64

def read_excel(self):
    wb = open_workbook(file_contents = base64.decodestring(obj.data))
    sheet = wb.sheets()[0]

    for s in wb.sheets():

         values = []

         for row in range(s.nrows):

             col_value = []

             for col in range(s.ncols):

                 value  = (s.cell(row,col).value)

                 try : value = str(int(value))

                 except : pass

                 col_value.append(value)

             values.append(col_value)

     print values