coercing to Unicode: need string or buffer, NoneType found。？？？

#!/usr/bin/env python
# -*- coding:utf-8 -*-

import xlrd
import Tkinter as tk
from xlutils.copy import copy
from xlwt import Style
import xlwt
import re


class excelMain(object):
    def __init__(self):
        self.createGUI()

    def createGUI(self):
        window = tk.Tk()
        window.title("                                                                              EXCEL-SUPPORTER")
        window.geometry("1300x700")
        self.var = tk.StringVar()
        self.l = tk.Label(window, textvariable=self.var, fg=("white"), bg='black', font=('Arial', 12), width=70, height=10)
        self.l.pack()

        self.e1 = tk.Entry(window, font=('Arial', 14))
        self.e2 = tk.Entry(window, font=('Arial', 14))
        self.e3 = tk.Entry(window, font=('Arial', 14))

        self.e1.pack()
        self.e2.pack()
        self.e3.pack()

        self.ll = tk.Label(window, text="请输入文件名，定额编号 , 数量", bg='white', fg='black', font=('Arial', 12), width=30, height=2)
        self.ll.pack()


        b = tk.Button(window, text='查找', font=('Arial', 12), width=10, height=1, command=self.buttonReturn)
        b.pack()

        window.mainloop()

    def buttonReturn(self):
        e2 = re.sub("-", "", self.e2.get())
        if e2.isalnum() == True:
            self.readExcel()
        else:
                self.var.set("请检查编号中是否有换行或空格")

    def writeExcel(self, styl=Style.default_style):
        name = self.e1.get()
        job = self.e2.get()
        num = self.e3.get()
        book = xlrd.open_workbook(str(name)+ ".xls", formatting_info=True)
        wb = copy(book)
        Data_sheet = book.sheet_by_name(u'表三丙')
        cols = Data_sheet.col_values(1)
        wb.get_sheet(5).write(4, int(cols.index(job)), str(num), styl)
        wb.save(str(name+ ".xls"))

    def readExcel(self):
        name = self.e1.get()
        book = xlrd.open_workbook(str(name)+ ".xls", formatting_info=True)
        Data_sheet = book.sheet_by_name(u'表三丙')
        cols = Data_sheet.col_values(1)
        if self.e2.get() in cols:
            style = xlwt.easyxf();
            self.writeExcel(style)
            self.var.set("修改成功")

        else:
            self.var.set("无")


excelMain()

报错为

C:\Python27\python.exe C:/Users/86138/Desktop/ex/main.py
Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Python27\lib\lib-tk\Tkinter.py", line 1547, in __call__
    return self.func(*args)
  File "C:/Users/86138/Desktop/ex/main.py", line 44, in buttonReturn
    self.readExcel()
  File "C:/Users/86138/Desktop/ex/main.py", line 66, in readExcel
    self.writeExcel(style)
  File "C:/Users/86138/Desktop/ex/main.py", line 57, in writeExcel
    wb.save(str(name+ ".xls"))
  File "C:\Python27\lib\site-packages\xlwt\Workbook.py", line 710, in save
    doc.save(filename_or_stream, self.get_biff_data())
  File "C:\Python27\lib\site-packages\xlwt\Workbook.py", line 667, in get_biff_data
    before += self.__all_fonts_num_formats_xf_styles_rec()
  File "C:\Python27\lib\site-packages\xlwt\Workbook.py", line 570, in __all_fonts_num_formats_xf_styles_rec
    return self.__styles.get_biff_data()
  File "C:\Python27\lib\site-packages\xlwt\Style.py", line 185, in get_biff_data
    result += self._all_num_formats()
  File "C:\Python27\lib\site-packages\xlwt\Style.py", line 209, in _all_num_formats
    result += NumberFormatRecord(fmtidx, fmtstr).get()
  File "C:\Python27\lib\site-packages\xlwt\BIFFRecords.py", line 785, in __init__
    ufmtstr = upack2(fmtstr)
  File "C:\Python27\lib\site-packages\xlwt\UnicodeUtils.py", line 50, in upack2
    us = unicode(s, encoding)
TypeError: coercing to Unicode: need string or buffer, NoneType found

https://blog.csdn.net/happen23/article/details/46683813