spreadsheet combines python-excel (xlrd, xlwt) and openpyxl to allow a single set of commands for editing .xls and .xlsx files in Python.

The commands for using this library can be found at the openpyxl site (http://pythonhosted.org/openpyxl/) with the only change being that openpyxl will be replaced with spreadsheet.

Examples:

""" Convert xlsx to xls or vice verse """
import spreadsheet

wb_xlsx = spreadsheet.load_workbook('demo1.xlsx')
wb_xls  = spreadsheet.load_workbook('demo2.xls')

wb_xlsx.save('demo1.xls')
wb_xls.save('demo2.xlsx')



""" Create a new spreadsheet and place the value 'Hello World' in cell A1 """
import spreadsheet

wb = spreadsheet.Workbook()
sh = wb.get_active_sheet()
sh.cell(row=0, column=0).value = 'Hello World'
wb.save('demo3.xlsx')


Installation:
Download these files and place them in PythonXX/Lib/site-packages/spreadsheet

Then it should work!