运行的时候一直提示是 not contain a loop with signature matching types dtype('

[weixin_38058113]

请教各位大侠，运行程序的时候，一直提示报错: Traceback (most recent call last):   File "C:/Python_3.6/Python_File_Py/EX_001/003.py", line 14, in <module>     address = house_num + ' ' + street + "," + city TypeError: ufunc 'add' did not contain a loop with signature matching types dtype('<U21') dtype('<U21') dtype('<U21') 代码如下: import xlrd # 导入xlrd模块 import requests # 导入requests模块 from datetime import date, datetime # 从模块datetime中导入函数date,datetime import pandas as pd # 导入pandas大熊猫模块，并将其命名为pd from math import sin, asin, cos, radians, fabs, sqrt loc_list = [], df = pd.read_excel('C:\Python_3.6\Python_File_Py\EX_001\\KS_01.xlsx') rows = df.iloc[:, 0].size # 行数 3 for indexs in df.index: street = df.loc[indexs].values[0] house_num = df.loc[indexs].values[1] city = df.loc[indexs].values[2] address = house_num + ' ' + street + "," + city print(address) 请问问题出在哪里啊