TypeError：在Python中过滤JSON中的值时，字符串索引必须为整数

You are iterating the base dictionary instead of iteration list under people

Iterate over z["people"] which contains a list, instead of iterating z
Solution

x = { "people": [{ "owner": "bob", "petname": "fido", "species": "dog", "size": "chunky"}, {"owner": "mary","petname": "marvin","species": "cat","size": "cat"}]}
    y = json.dumps(x)
    z = json.loads(y)
    for i in z["people"]:
        if i["owner"] == "bob":
            print(i['petname'])
            break

码：

x = { "people": [{ "owner": "bob", "petname": "fido", "species": "dog", "size": "chunky"}, {"owner": "mary","petname": "marvin","species": "cat","size": "cat"}]}
people = x["people"]
for i in people:
    if i["owner"] == "bob":
        print(i['petname'])
        break

If you need JSON:

import json
x = { "people": [{ "owner": "bob", "petname": "fido", "species": "dog", "size": "chunky"}, {"owner": "mary","petname": "marvin","species": "cat","size": "cat"}]}
y = json.dumps(x)
z = json.loads(y)
people = x["people"]
for i in people:
    if i["owner"] == "bob":
        print(i['petname'])
        break

输出：

fido

当你做

for i in z:

每个密钥都被获取，即，i ='people'。所以当你这样做

i["owner"]

产生错误，因为我是一个字符串。 因此使用：

for i in z:
    if z[i]["owner"] == "bob":
        print(z[i]['petname'])
        break