Python TypeError：只能将str（而不是“ tuple”）连接到str

Question

我正在尝试打印SQL输出，如下所示：

dwh_cur.execute("""select count (*) from sales""")
var1 = dwh_cur.fetchone()
text = 'Total Sales is ' + var1

var1 = 100

预期输出：

Total Sales is 100

但是我得到一个错误

TypeError: can only concatenate str (not "tuple") to str

Answer 1

dwh_cur.fetchone（）返回一个元组，请尝试以下操作：

import os
import errno
import boto3
import botocore


resource = boto3.resource('s3')
bucket = resource.Bucket('my-bucket')
client = boto3.client('s3')

def download_dir():
objList = client.list_objects(Bucket='my-bucket')['Contents']
for obj in objList:
    obj_Key = obj['Key']
    path,_destPath = os.path.split(obj_Key)
    print ("Downloading file :"+ obj_Key);
    client.download_file('my-bucket', obj_Key, _destPath)

download_dir()

Answer 2

好dwh_cur.fetchone（）返回一条记录，该记录表示为元素的元组，

dwh_cur.execute("""select count (*) from sales""")
var1 = dwh_cur.fetchone()
text = 'Total Sales is {}'.format(var1[0])

可能会根据查询返回的内容工作。