转载：http://blog.csdn.net/hqzxsc2006/article/details/51768351
import os
import xlrd
import xlwt
from xlutils.copy import copy
def excelwrite(L=None):
if L is None:
L = []
print(L)
filename = r'wldata.xls'
workbook = xlrd.open_workbook(filename, formatting_info=True)
sheet = workbook.sheet_by_index(0)
rowNum = sheet.nrows
colNum = sheet.ncols
newbook = copy(workbook)
newsheet = newbook.get_sheet(0)
# 在末尾增加新行
str = 'hehe'
newsheet.write(rowNum, 0, str)
# 覆盖保存
newbook.save(filename)