Python：base64 库高级用法举例和应用详解

import base64

# 场景：将短文本信息编码，以便在不安全的环境中传输
message = "Hello, Python!"
# 将字符串编码为字节
message_bytes = message.encode('utf-8')
# 将字节编码为base64
base64_bytes = base64.b64encode(message_bytes)
# 将base64字节转换为字符串
base64_message = base64_bytes.decode('utf-8')

print(f"Encoded Message: {base64_message}")

# 解码过程
# 将base64字符串重编码为字节
base64_bytes = base64_message.encode('utf-8')
# 从base64字节解码为原始字节
message_bytes = base64.b64decode(base64_bytes)
# 将原始字节解码为字符串
message = message_bytes.decode('utf-8')

print(f"Decoded Message: {message}")

import base64

# 场景：将图片文件的内容编码为base64文本，便于嵌入HTML或 JSON
def encode_file(file_path):
    with open(file_path, 'rb') as file:
        file_content = file.read()
        base64_encoded = base64.b64encode(file_content)
        return base64_encoded.decode('utf-8')

def decode_file(base64_content, output_path):
    file_content = base64.b64decode(base64_content)
    with open(output_path, 'wb') as file:
        file.write(file_content)

input_file = 'example.jpg'  # 原始文件路径
encoded_content = encode_file(input_file)
print(f"Encoded file content: {encoded_content[:60]}...")  # 显示一部分编码内容，防止过长

output_file = 'decoded_example.jpg'  # 输出文件路径
decode_file(encoded_content, output_file)
print(f"File decoded and saved as: {output_file}")

import base64
import json

# 场景：生成一个base64编码的JSON串，用作URL安全的token
data = {
    'username': 'travis',
    'access_level': 'admin'
}

# 将字典转换为JSON字符串
json_string = json.dumps(data)
# 将JSON字符串转换为字节，并进行URL安全的base64编码
base64_encoded = base64.urlsafe_b64encode(json_string.encode('utf-8')).decode('utf-8')
print(f"Encoded token: {base64_encoded}")

# 解码过程
# 将URL安全的base64字符串转换回字节
base64_decoded = base64.urlsafe_b64decode(base64_encoded)
# 从字节解码回JSON字符串，并解析为字典
decoded_data = json.loads(base64_decoded.decode('utf-8'))
print(f"Decoded data: {decoded_data}")