Python中将JSON数据写入文件的实现方法

import json

data = {
    "name": "John",
    "age": 30,
    "city": "New York"
}

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

json_string = json.dumps(data)
with open('data.json', 'w') as f:
    f.write(json_string)

import json

# 准备JSON数据
data = {
    "a list": [1, 42, 3.141, 1337, 'help', '€'],
    "a string": "bla",
    "another dict": {
        "foo": "bar",
        "key": "value",
        "the answer": 42
    }
}

# 写入JSON文件
with open('data.json', 'w', encoding='utf-8') as f:
    json.dump(data, f, ensure_ascii=False, indent=4)

# 读取JSON文件
with open('data.json') as data_file:
    data_loaded = json.load(data_file)

print(data == data_loaded)

with open('data.json', 'w', encoding='utf-8') as f:
    json.dump(data, f, ensure_ascii=False, indent=4, sort_keys=True)

with open('data.json', 'w', encoding='utf-8') as f:
    json.dump(data, f, ensure_ascii=False)

import json
data = {"price": "€10"}
print(json.dumps(data))  # 输出: '{"price": "\\u20ac10"}'
print(json.dumps(data, ensure_ascii=False))  # 输出: '{"price": "€10"}'

import json
import numpy as np

class NumpyEncoder(json.JSONEncoder):
    """ Special json encoder for np types """
    def default(self, obj):
        if isinstance(obj, (np.int_, np.intc, np.intp, np.int8,
                            np.int16, np.int32, np.int64, np.uint8,
                            np.uint16, np.uint32, np.uint64)):
            return int(obj)
        elif isinstance(obj, (np.float_, np.float16, np.float32,
                              np.float64)):
            return float(obj)
        elif isinstance(obj, (np.ndarray,)):
            return obj.tolist()
        return json.JSONEncoder.default(self, obj)

my_data = {'array': np.array([1, 2, 3])}
with open('my_filename.json', 'w') as f:
    json.dump(my_data, f, indent=4, cls=NumpyEncoder)