Python如何调用API？网络请求实战指南

import requests

# 简单GET请求
try:
    response = requests.get('https://api.example.com/weather', params={'city': 'Beijing'})
    response.raise_for_status()  # 如果状态码不是200，抛出HTTPError
    print("天气数据:", response.json())
except requests.exceptions.RequestException as e:
    print(f"请求失败了，问题出在这里：{e}")

import requests
import json

# POST请求，发送JSON数据
url = 'https://api.example.com/register'
headers = {'Content-Type': 'application/json'} # 告诉服务器我发的是JSON
data = {
    'username': 'python_user',
    'password': 'secure_password123',
    'email': 'user@example.com'
}

try:
    # 推荐这种方式，requests会自动处理json编码
    response = requests.post(url, headers=headers, json=data)
    response.raise_for_status()
    print("注册结果:", response.json())
except requests.exceptions.RequestException as e:
    print(f"注册请求出错了：{e}")

import requests

try:
    response = requests.get('https://api.example.com/sometimes_fail', timeout=5) # 设置超时
    response.raise_for_status()
    print("数据获取成功:", response.json())
except requests.exceptions.Timeout:
    print("请求超时了，服务器响应太慢。")
except requests.exceptions.HTTPError as err:
    print(f"HTTP错误发生了：{err}，状态码：{response.status_code}")
except requests.exceptions.ConnectionError as err:
    print(f"网络连接有问题：{err}，检查你的网络。")
except requests.exceptions.RequestException as err:
    print(f"其他请求错误：{err}")

# 伪代码，展示重试逻辑
import time

max_retries = 3
for i in range(max_retries):
    try:
        response = requests.get('https://api.example.com/unstable', timeout=5)
        response.raise_for_status()
        print("重试成功:", response.json())
        break # 成功就跳出循环
    except requests.exceptions.RequestException as e:
        print(f"第 {i+1} 次请求失败: {e}")
        if i < max_retries - 1:
            sleep_time = 2 ** i # 指数退避
            print(f"等待 {sleep_time} 秒后重试...")
            time.sleep(sleep_time)
        else:
            print("所有重试都失败了。")