Python请求异常处理

Question

如何使用python库请求处理异常？例如,如何检查PC是否连接到互联网？

当我尝试

try:
    requests.get('http://www.google.com')
except ConnectionError:
    # handle the exception

它给我的错误名称ConnectionError没有定义

Answer 1

假设你做了import requests,你想要requests.ConnectionError.ConnectionError是由...定义的例外requests.请在此处查看API文档.

因此代码应该是:

try:
   requests.get('http://www.google.com')
except requests.ConnectionError:
   # handle the exception

Answer 2

根据文档，我添加了以下几点：-

1. 如果出现网络问题（拒绝连接，例如互联网问题），Requests 将引发 ConnectionError 异常。

   try:
      requests.get('http://www.google.com')
   except requests.ConnectionError:
      # handle ConnectionError the exception
   

2. 如果出现罕见的无效 HTTP 响应，Requests 将引发 HTTPError 异常。如果 HTTP 请求返回不成功的状态代码，Response.raise_for_status() 将引发 HTTPError。

   try:
      r = requests.get('http://www.google.com/nowhere')
      r.raise_for_status()
   except requests.exceptions.HTTPError as err:
      #handle the HTTPError request here
   

3. 如果请求超时，则会引发 Timeout 异常。

   您可以使用超时参数告诉请求在给定秒数后停止等待响应。

   requests.get('https://github.com/', timeout=0.001)
   # timeout is not a time limit on the entire response download; rather, 
   # an exception is raised if the server has not issued a response for
   # timeout seconds
   

4. Requests 显式引发的所有异常都继承自 requests.exceptions.RequestException。所以基本处理程序看起来像，

   try:
      r = requests.get(url)
   except requests.exceptions.RequestException as e:
      # handle all the errors here
   

Answer 3

为清楚起见,那就是

except requests.ConnectionError:

不

import requests.ConnectionError

 

您还可以捕获一般异常(尽管不建议这样做)

except Exception:

Answer 4

使用import requests.

实现异常处理总是好的。它不仅有助于避免脚本意外退出，还有助于记录错误和信息通知。使用 Python 请求时，我更喜欢捕获这样的异常：

try:
    res = requests.get(adress,timeout=30)
except requests.ConnectionError as e:
    print("OOPS!! Connection Error. Make sure you are connected to Internet. Technical Details given below.\n")
    print(str(e))            
    continue
except requests.Timeout as e:
    print("OOPS!! Timeout Error")
    print(str(e))
    continue
except requests.RequestException as e:
    print("OOPS!! General Error")
    print(str(e))
    continue
except KeyboardInterrupt:
    print("Someone closed the program")

Answer 5

实际上，除了之外，还会requests.get()产生更多的异常ConnectionError。这是我在生产中看到的一些东西：

from requests import ReadTimeout, ConnectTimeout, HTTPError, Timeout, ConnectionError

try:
    r = requests.get(url, timeout=6.0)
except (ConnectTimeout, HTTPError, ReadTimeout, Timeout, ConnectionError):
    continue