Python Learning notes-exceptions

Python run-time errors are called exceptions

    1. Syntax error : The software is structurally faulty and cannot be interpreted by the interpreter or compiled by the compiler.

2. Logic error : Due to incomplete or illegal input, it may be that the logic can not survive, the calculation or the output of the required process can not be executed and so on.

A Python exception is an object that represents an error or unexpected condition

An exception is triggered when Python detects an error

1.python can pass an anomaly through an abnormal conduction mechanism, emitting a signal that an abnormal condition occurs.

2. Programmers can also manually trigger exceptions in the code

python Exceptions can also be understood as: behavior that occurs when a program has errors and is taken outside of the normal control flow

First stage: The interpreter triggers an exception, at which time the current flow of the program is interrupted

Phase two: exception handling, such as ignoring non-fatal errors, mitigating the effects of errors, etc.

The function of the anomaly

  Error handling:

default processing for Python: Stop programs, print error messages

Handling exceptions and recovering from exceptions using a try statement

Event Notification:

Used to emit a valid status signal

Special case Processing:

Unable to adjust the code to handle the scene

termination Behavior:

The try/finally statement ensures that the necessary end-handling mechanism is performed

Unconventional control processes:

An exception is an advanced jump (goto) mechanism

Detecting and Handling exceptions

Exceptions are detected by a try statement

any code in a try statement block will be detected to detect the occurrence of an exception     

There are two main forms of a try statement:

try-except: Detecting and Handling exceptions

can have multiple except

Support for using the ELSE clause to handle code for execution without probing exceptions

try-finally: Check for exceptions only and do some cleanup work as necessary

Compound form of Try statement

try-except-finally

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Python Learning notes-exceptions