How to process JSON data in Python

Python is a powerful programming language that provides good support for processing JSON data. This article will introduce how to use Python to read and write JSON data and provide specific code examples.

JSON (JavaScript Object Notation) is a lightweight format for data exchange. It is easy to read and write, and is widely used in network communication and data storage. Python provides the json module, which can easily handle JSON data.

Reading JSON data

Python's json module provides the loads() function for converting JSON strings into Python objects.

The following is a sample code for reading JSON data:

import json

# JSON字符串
json_str = '{"name": "Alice", "age": 25, "city": "New York"}'

# 将JSON字符串转换为Python对象
data = json.loads(json_str)

# 读取JSON数据
name = data['name']
age = data['age']
city = data['city']

# 输出结果
print('Name:', name)
print('Age:', age)
print('City:', city)

In the above code, we first imported the json module. Then, a JSON string json_str is defined, which contains a character named name, age age and city city Object. Next, we use the json.loads() function to convert the JSON string into a Python object data. Finally, we read each field of the JSON data through data['key'] and output the results.

Writing JSON data

Python's json module provides the dumps() function for converting Python objects into JSON strings.

The following is a sample code for writing JSON data:

import json

# Python对象
data = {
    'name': 'Bob',
    'age': 30,
    'city': 'London'
}

# 将Python对象转换为JSON字符串
json_str = json.dumps(data)

# 输出结果
print('JSON String:', json_str)

In the above code, we first imported the json module. Then, a Python dictionary data is defined, which contains a child named name, age age and city city object. Next, we use the json.dumps() function to convert the Python object to a JSON string and assign the result to the variable json_str. Finally, we output the converted JSON string.

Reading and writing JSON files

In addition to reading JSON data into memory for processing, we can also read and write JSON data directly into files.

The following is a sample code for reading and writing JSON files:

import json

# 读取JSON文件
with open('data.json', 'r') as file:
    json_str = file.read()
    data = json.loads(json_str)

# 读取JSON数据
name = data['name']
age = data['age']
city = data['city']

# 输出结果
print('Name:', name)
print('Age:', age)
print('City:', city)

# 写入JSON文件
data['email'] = 'bob@example.com'
with open('data.json', 'w') as file:
    json.dump(data, file)

In the above code, we first use the open() function to open a file named data.json JSON file, and use the file.read() function to read the file content. Then, use the json.loads() function to convert the JSON string into a Python object. Next, we read the JSON data by the key of the data and output the result.

Then, we add the email field of the data object data as bob@example.com and use json.dump ()The function writes the data object to the JSON file.

The above are methods and code examples for using Python to read and write JSON data. Through Python's json module, we can easily process JSON data and read and write data.

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