更新JSON对象

import json

# 假设我们有一个JSON字符串
json_str = '{"name": "Alice", "age": 30, "city": "New York"}'

# 解析JSON字符串为Python字典
data = json.loads(json_str)

# 更新字典中的值
data['age'] = 31
data['city'] = 'Los Angeles'

# 将更新后的字典转换回JSON字符串
updated_json_str = json.dumps(data, indent=4)

print(updated_json_str)

{
    "name": "Alice",
    "age": 31,
    "city": "Los Angeles"
}

if 'age' in data:
    data['age'] = 31
else:
    data['age'] = 0  # 默认值

# 错误示例
data['age'] = 'thirty-one'  # 错误，age应该是数字

# 正确示例
data['age'] = 31  # 正确

try:
    data = json.loads(json_str)
except json.JSONDecodeError as e:
    print(f"JSON解析错误: {e}")