Requests 库的详细使用指南，覆盖安装、常用方法、高级功能及示例代码：

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1. 安装

pip install requests

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2. 基础用法

GET 请求

import requests

response = requests.get("https://api.example.com/data")
print(response.status_code)  # 200
print(response.text)  # 响应文本
print(response.json())  # 解析为 JSON（自动处理）

POST 请求

payload = {"key1": "value1", "key2": "value2"}
response = requests.post("https://httpbin.org/post", data=payload)
print(response.json())

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3. 请求参数

查询参数（URL 参数）

params = {"q": "python", "page": 2}
response = requests.get("https://httpbin.org/get", params=params)
print(response.url)  # https://httpbin.org/get?q=python&page=2

请求头

headers = {"User-Agent": "Mozilla/5.0", "Authorization": "Bearer YOUR_TOKEN"}
response = requests.get("https://api.example.com", headers=headers)

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4. 响应处理

检查状态码

if response.status_code == 200:
    print("成功!")
else:
    print(f"失败: {response.status_code}")

处理二进制内容（如图片）

image_url = "https://example.com/image.jpg"
response = requests.get(image_url)
with open("image.jpg", "wb") as f:
    f.write(response.content)

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5. 高级功能

会话保持（Session）

with requests.Session() as session:
    session.headers.update({"User-Agent": "Custom-Agent"})
    # 登录（保持 Cookies）
    session.post("https://example.com/login", data={"user": "admin", "pass": "123"})
    # 后续请求自动携带 Cookies
    response = session.get("https://example.com/dashboard")

超时设置

try:
    response = requests.get("https://example.com", timeout=5)  # 5秒超时
except requests.exceptions.Timeout:
    print("请求超时")

重试机制

from requests.adapters import HTTPAdapter
from requests.packages.urllib3.util.retry import Retry

session = requests.Session()
retries = Retry(total=3, backoff_factor=1, status_forcelist=[500, 502, 503, 504])
session.mount("https://", HTTPAdapter(max_retries=retries))
response = session.get("https://example.com")

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6. 处理认证

Basic Auth

from requests.auth import HTTPBasicAuth

response = requests.get(
    "https://api.example.com",
    auth=HTTPBasicAuth("user", "pass")
)

Token 认证

headers = {"Authorization": "Token YOUR_API_TOKEN"}
response = requests.get("https://api.example.com", headers=headers)

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7. 代理配置

proxies = {
    "http": "http://10.10.1.10:3128",
    "https": "http://10.10.1.10:1080",
}
response = requests.get("https://example.com", proxies=proxies)

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8. 文件上传

files = {"file": open("data.txt", "rb")}
response = requests.post("https://httpbin.org/post", files=files)

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9. 错误处理

try:
    response = requests.get("https://example.com")
    response.raise_for_status()  # 自动抛出 4xx/5xx 错误
except requests.exceptions.HTTPError as err:
    print(f"HTTP 错误: {err}")
except requests.exceptions.RequestException as err:
    print(f"请求异常: {err}")

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10. 常见场景

调用 REST API

response = requests.get("https://api.github.com/users/octocat")
data = response.json()
print(data["name"], data["bio"])

爬取动态内容（需结合其他工具）

# 若页面内容由 JavaScript 渲染，需改用 Selenium/Playwright
response = requests.get("https://example.com/dynamic-page")
# 解析静态 HTML（结合 BeautifulSoup）
from bs4 import BeautifulSoup

soup = BeautifulSoup(response.text, "html.parser")
title = soup.find("h1").text

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注意事项

• 遵守 Robots 协议：检查目标网站的 robots.txt。
• 速率限制：避免高频请求导致 IP 被封。
• SSL 验证：若遇到证书错误，可关闭验证（不推荐）：

  requests.get("https://example.com", verify=False)

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通过 Requests，可以快速完成 HTTP 请求交互，适用于 API 调用、简单爬虫、数据采集等场景。对于高并发需求，建议使用异步库（如 aiohttp）。