Excel XLSX DictReader in Python 3

xlsx_reader.py

import xlrd, mmap

def XLSDictReader(filename, sheet_index=0):
    '''
        Excel xlsd dict reader.
    '''
    with open(filename) as f:
        book = xlrd.open_workbook(
            file_contents=mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ))

        sheet = book.sheet_by_index(sheet_index)
        headers = dict((i, sheet.cell_value(0, i)) for i in range(sheet.ncols))

    return (dict((headers[j], sheet.cell_value(i, j)) for j in headers)
            for i in range(1, sheet.nrows))

r = XLSDictReader('somefile')
for line in r:
    print(line)