python中string不能合并到一个列表

Question

1.题目描述及期望结果
从data中提取出x，然后相加。期望结果为9。

data ='''[
{ "id" : "001","x" : "2"} ,
{ "id" : "009","x" : "7"}
]'''

2.相关代码

import ssl
import json

ctx = ssl.create_default_context()
ctx.check_hostname = False
ctx.verify_mode = ssl.CERT_NONE

data ='''[
{ "id" : "001","x" : "2"} ,
{ "id" : "009","x" : "7"}
]'''
info = json.loads(data)
for item in info:
x1=item['x']
x3=[]
for x2 in x1:
x3.append(int(x2))
print(x3)

3.执行结果
[2]
[7]
无法将这两个数字放在一个列表中，导致无法加和

Answer 1

import json
data = '''[
{ "id" : "001","x" : "2"} ,
{ "id" : "009","x" : "7"}
]'''
sum = 0
info = json.loads(data)
for item in data:
    sum += int(item['x'])
print sum

Answer 2

import json

data = '''[
{ "id" : "001","x" : "2"} ,
{ "id" : "009","x" : "7"}
]'''
new_data = json.loads(data)
num_list = [int(num['x']) for num in new_data]
print(sum(num_list))