此脚本仅用于演示目的，通常在解析某些数据时会给出lxml.etree._ElementUnicodeResult类型。由于某种原因，无法使用openpyxl将这种类型的字符串写入Excel。这种字符串是某种错误还是预期的行为？
from openpyxl import Workbook
import lxml
string_to_write = lxml.etree._ElementUnicodeResult("just a string")
outfile = Workbook()
ws = outfile["Sheet"]
ws.cell(row=1, column=1).value = "just a string"
ws.cell(row=1, column=2).value = string_to_write
outfile.save("output.xlsx")