#Python Requests 库使用教程：告别 urllib 的繁琐

import requests

import requests

# 发送一个简单的 GET 请求
response = requests.get('https://httpbin.org/get')

# 打印响应文本（自动处理编码，无需手动 decode）
print(response.text)

# 准备要提交的表单数据
form_data = {'username': 'python_user', 'email': 'user@example.com'}

# 发送 POST 请求
response = requests.post('https://httpbin.org/post', data=form_data)

# 直接解析 JSON 响应（httpbin 会原样返回你发送的请求详情）
print(response.json())

requests.put('https://httpbin.org/put', data={'key': 'update_value'})
requests.delete('https://httpbin.org/delete')
requests.head('https://httpbin.org/get')        # 只获取响应头
requests.options('https://httpbin.org/get')     # 查看服务器支持的方法

query_params = {'page': 1, 'limit': 20, 'sort': 'newest'}

response = requests.get('https://httpbin.org/get', params=query_params)

# 查看拼接后的完整 URL
print(response.url)  # 输出：https://httpbin.org/get?page=1&limit=20&sort=newest

custom_headers = {
    'User-Agent': 'My-Python-App/1.0.0',          # 自定义客户端标识
    'Authorization': 'Bearer YOUR_API_TOKEN',     # 常见的 Bearer Token 认证
}

response = requests.get('https://api.example.com/data', headers=custom_headers)

# 注意：不需要额外导入 json 库
json_data = {
    'title': 'Python Requests',
    'content': 'This is a tutorial'
}

response = requests.post('https://httpbin.org/post', json=json_data)

response = requests.get('https://httpbin.org/get')

# 文本
print("=== 响应文本（前100字符） ===")
print(response.text[:100])

# 二进制（例如保存一张图片）
img_response = requests.get('https://httpbin.org/image/png')
with open('test.png', 'wb') as f:
    f.write(img_response.content)

# JSON
print("\n=== JSON 响应中的 origin ===")
print(response.json()['origin'])

response = requests.get('https://httpbin.org/status/404')  # 模拟 404 错误

print(f"状态码：{response.status_code}")

# 结合 try-except 让错误处理更安全
try:
    response.raise_for_status()
except requests.exceptions.HTTPError as e:
    print(f"HTTP 错误：{e}")

response = requests.get('https://httpbin.org/get')

print("Content-Type:", response.headers['content-type'])
print("Server:", response.headers.get('Server'))   # 推荐使用 get 方法避免 KeyError

# 创建一个会话
session = requests.Session()

# 设置会话级别的请求头（该会话内所有请求都会自动携带）
session.headers.update({'User-Agent': 'My-Session-App/1.0'})

# 第一次请求：模拟设置 Cookie
login_response = session.post('https://httpbin.org/cookies/set', params={'session_id': '123456'})
print("第一次请求后设置的 Cookie：", login_response.json())

# 第二次请求：自动携带上次的 Cookie
data_response = session.get('https://httpbin.org/cookies')
print("第二次请求时服务器收到的 Cookie：", data_response.json())

# 使用完毕后记得关闭会话
session.close()

# 临时禁用 SSL 验证（仅用于测试，会抛出一个安全警告）
requests.get('https://self-signed.badssl.com', verify=False)

# 生产环境中可以指定自己的 CA 证书
requests.get('https://internal-api.example.com', verify='/path/to/your/ca-cert.pem')

# 连接超时 3 秒，读取超时 27 秒
requests.get('https://httpbin.org/delay/5', timeout=(3, 27))

# 总超时 5 秒
try:
    requests.get('https://httpbin.org/delay/10', timeout=5)
except requests.exceptions.Timeout as e:
    print("请求超时：", e)

from requests.exceptions import (
    RequestException,   # 所有 Requests 异常的父类，可做兜底
    HTTPError,
    Timeout,
    ConnectionError,
)

try:
    response = requests.get('https://httpbin.org/status/500', timeout=5)
    response.raise_for_status()   # 先检查 HTTP 状态码
except HTTPError as e:
    print(f"HTTP 错误（状态码 >=400）：{e}")
except Timeout as e:
    print(f"请求超时：{e}")
except ConnectionError as e:
    print(f"连接错误（如网络不通、DNS 解析失败）：{e}")
except RequestException as e:
    print(f"其他 Requests 错误：{e}")