urllib3中没有默认密码属性吗？

import urllib3
import base64

# 创建一个HTTP连接池
http = urllib3.PoolManager()

# 设置用户名和密码
username = 'your_username'
password = 'your_password'

# 编码凭证信息
credentials = base64.b64encode(f'{username}:{password}'.encode('utf-8')).decode('utf-8')

# 添加Authorization字段到请求头
headers = {
    'Authorization': f'Basic {credentials}'
}

# 发起GET请求
response = http.request('GET', 'http://example.com', headers=headers)

# 处理响应
print(response.status)
print(response.data)