python - exception

category:

1. try/except #Catch exceptions and recover, slightly different from languages ​​such as java     

2. try/finally # Regardless of whether an exception occurs, the finally statement is executed, even if try and except contain return 

3.raise #Manually trigger an exception in the code

4.assert #Conditionally trigger an exception in the program, which can be regarded as a conditional raise  statement

5.with/as #implement environment manager

6. try/except/else #Execute except when an exception occurs, and execute else when it does not occur

try/except/else/finally can be used in combination, there can be multiple excepts, but there can only be one else and finally