Python中JSON转换的全面指南与最佳实践

import json

data = {
    "name": "John Doe",
    "age": 30,
    "is_employee": True,
    "skills": ["Python", "JavaScript", "SQL"],
    "address": {
        "street": "123 Main St",
        "city": "New York"
    }
}

json_string = json.dumps(data)
print(json_string)

{"name": "John Doe", "age": 30, "is_employee": true, "skills": ["Python", "JavaScript", "SQL"], "address": {"street": "123 Main St", "city": "New York"}}

json_data = '{"name": "John Doe", "age": 30, "is_employee": true}'
python_obj = json.loads(json_data)
print(python_obj)
print(type(python_obj))

{'name': 'John Doe', 'age': 30, 'is_employee': True}
<class 'dict'>

with open('data.json', 'w') as f:
    json.dump(data, f)

with open('data.json', 'r') as f:
    loaded_data = json.load(f)
print(loaded_data)

pretty_json = json.dumps(data, indent=4, sort_keys=True)
print(pretty_json)

{
    "address": {
        "city": "New York",
        "street": "123 Main St"
    },
    "age": 30,
    "is_employee": true,
    "name": "John Doe",
    "skills": [
        "Python",
        "JavaScript",
        "SQL"
    ]
}

from datetime import datetime
import json

class CustomEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, datetime):
            return obj.isoformat()
        return super().default(obj)

data = {
    "event": "Conference",
    "date": datetime.now()
}

json_string = json.dumps(data, cls=CustomEncoder)
print(json_string)

data = {
    "temperature": float('nan'),
    "distance": float('inf')
}

json_string = json.dumps(data, allow_nan=True)  # 默认就是True
print(json_string)

import ijson

with open('large_file.json', 'rb') as f:
    for prefix, event, value in ijson.parse(f):
        print(f"prefix: {prefix}, event: {event}, value: {value}")

from datetime import datetime

data = {"timestamp": datetime.now().isoformat()}

data = {"timestamp": datetime.now().timestamp()}

a = {}
b = {'a': a}
a['b'] = b

# 这会抛出 TypeError: Circular reference detected
# json.dumps(a)

try:
    data = json.loads(json_string)
except json.JSONDecodeError as e:
    print(f"Invalid JSON: {e}")