Brief introduction to exception handling in Python

This article describes how to handle exceptions in Python. This article describes how to detect exceptions in try-retry T and how to use the context manager (... As... Statement), raise raises exceptions, assertions, and so on. For more information, see The python exception handling mechanism. it is similar to java and uses the try-try T-finally structure.

Try-try T to detect exceptions

Format

The code is as follows:

Try:
Try_statement
Except t (ErrorType1, ErrorType2), e:
Handle_statement
Finally:
Finally_statement

Instance

The code is as follows:

#! /Usr/bin/python
Try:
A = 12
B = 0
C = a/B
Except t Exception, e:
Print "Exception occurs:", e
Finally:
Print "finally handle! "

Context manager (... As... Statement)

The with statement is particularly applicable to scenarios where the resource is first opened and finally released, because it automatically releases the occupied resources and does not need to be explicitly released.

Format

The code is as follows:

With context_expr [as var]:
With_statement

Raise exception

Format

The code is as follows:

Raise Exception [, args] or raise Exception (args)

Instance

The code is as follows:

Raise Exception ('exampleexception ')

Assertions

Checks the key points of the program. AssertError is triggered when the AssertError is unsuccessful)
The format is as follows:

The code is as follows:

Assert expression [, arguements]