##### requests 异常
```python
exception requests.ConnectionError(*args, **kwargs)
# 发生连接错误
exception requests.HTTPError(*args, **kwargs)
# HTTP错误异常
exception requests.URLRequired(*args, **kwargs)
# URL缺失异常
exception requests.TooManyRedirects(*args, **kwargs)
# 超过最大重定向次数，产生重定向异常
exception requests.ConnectTimeout(*args, **kwargs)
# 连接远程服务器超时异常
exception requests.Timeout(*args, **kwargs)
# 请求URL超时，产生超时异常
```
##### 示例
```python
import requests
try:
response = requests.get('https://www.baidu.com', timeout=5) # 设置超时时间为5秒
print(response.raise_for_status())
except requests.Timeout:
print("Request timed out")
except requests.exceptions.HTTPError as e:
print("HTTPError:", e)
except requests.exceptions.RequestException as e:
print("RequestException:", e)
```