How to process JSON data in Python

How to process JSON data in Python requires specific code examples

Introduction

JSON (JavaScript Object Notation) is a commonly used Data exchange format, widely used for data transfer between various programming languages ​​and platforms. In Python, we can use the built-in json module to process JSON data. This article will introduce how to use the json module in Python to parse and generate JSON data, and provide some specific code examples.

Parsing JSON data

When we need to get values ​​from JSON data, we can use the json.loads() function to parse the JSON string. Here is a simple example:

import json

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

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

# 获取值
name = data["name"]
age = data["age"]

print(name)  # 输出: Alice
print(age)  # 输出: 25

In the above example, we first import the json module. Then, we define a string json_str that contains JSON data. Next, we use the json.loads() function to parse the string into a Python object. Finally, we can get the value by key.

Generate JSON data

When we need to convert a Python object into a JSON string, we can use the json.dumps() function. Here is an example:

import json

# Python对象
data = {
    "name": "Bob",
    "age": 30
}

# 生成JSON字符串
json_str = json.dumps(data)

print(json_str)  # 输出: {"name": "Bob", "age": 30}

In the above example, we have defined a dictionary object data which contains name and age. We then use the json.dumps() function to convert the Python object into a JSON string. Finally, we print out the generated JSON string.

Handling nested JSON data

Sometimes, JSON data may contain nested structures. In this case, we can use recursion to process nested JSON data. Here is an example:

import json

# JSON字符串
json_str = '{"name": "Alice", "age": 25, "children": [{"name": "Bob", "age": 5}, {"name": "Charlie", "age": 3}]}'

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

# 获取值
name = data["name"]
age = data["age"]
children = data["children"]

# 遍历子对象
for child in children:
    child_name = child["name"]
    child_age = child["age"]
    print(child_name, child_age)

print(name)  # 输出: Alice
print(age)  # 输出: 25

In the above example, we have defined a JSON string containing nested structures json_str. We use the json.loads() function to parse the string into a Python object and get the value by key. When we encounter nested structures, we can iterate through the sub-objects by key and get their values.

Processing JSON data in files

In addition to processing JSON strings, we can also process JSON data stored in files. Here is an example:

import json

# 打开文件
with open("data.json") as file:
    # 解析JSON数据
    data = json.load(file)

# 获取值
name = data["name"]
age = data["age"]

print(name)  # 输出: Alice
print(age)  # 输出: 25

In the above example, we use the open() function to open a file named data.json and use json.load()Function parses JSON data from a file. We can then get the value by key.

Summary

This article introduces how to process JSON data in Python and provides some specific code examples. Whether parsing JSON data or generating JSON data, the json module can help us process JSON data easily. I hope this article can help readers better apply the json module to deal with JSON data problems.

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