python中将字典形式的数据循环插入Excel

list=[["2891-1","D"],["2892-1",["2896-1","B"],["2913-1",0],["2913-2",1],["2913-3",1]]

# -*- coding: utf-8 -*-
import pymysql
import json
import re
from xlsxwriter import Workbook
datanew = {}
#result数据是查询数据库中的list
for item in result:
  datanew[item['login_name']] = list(eval(item['answer']))
 #创建一个新的xlsx文件(如果原有同名文件会被覆盖)
book = xlsxwriter.Workbook('C:/Users/Administrator/Desktop/xxx.xlsx')
 #创建一个新的表单，默认名称为 “sheet1”，输入字符参数可指定名称
sheet1 = book.add_worksheet()
#字典数据
#循环字典key 的值
num = [a for a in datanew] 
lennum=len(num)
for a in range(lennum):
  lena=len(datanew[num[a]]);
  lena1=datanew[num[a]];  
  try:
    print(lena1)
    lena1.sort()
  except Exception as e:
    print(e)
  a1=num[a]
  sheet1.write(a+1,a1)
  b1x=[]
  for b in range(lena):
    b1=(lena1[b])[0]
    b2=(lena1[b])[1]
    b1x.append(b1);
    sheet1.write(a+1,b+1,b2)
  if a==0:  
    for y in range (len(b1x)):
      bx=b1x[y]
      sheet1.write(0,y+1,bx)
book.close()