What are the exception handling techniques in Python?

What are the exception handling techniques in Python? Need specific code examples

Python is a programming language that is easy to learn and use. It provides a powerful exception handling mechanism that can help programmers enhance the reliability and maintainability of their code. When writing Python programs, we often encounter various abnormal situations, such as file reading and writing errors, network connection problems, numerical calculation errors, etc. In order to ensure the normal operation of the program, we need to handle these abnormal situations reasonably.

The following introduces several commonly used Python exception handling techniques and gives corresponding code examples.

1. try-except statement
   This statement is used to catch and handle exceptions. In the try code block, we write the code that may cause an exception; in the except code block, we handle the logic of the exception. If an exception occurs during the execution of the code in the try code block, Python will immediately jump to the except code block to execute the corresponding processing code.

Code example:

try:
    # 可能会引发异常的代码
    result = 10 / 0
except ZeroDivisionError:
    # 处理除零异常
    print("除零错误")

2. Multiple exception catching
   In the except code block, we can handle multiple exceptions of different types. To achieve this purpose, we can use multiple except clauses.

Code example:

try:
    # 可能会引发异常的代码
    result = 10 / 0
except ZeroDivisionError:
    # 处理除零异常
    print("除零错误")
except ValueError:
    # 处理值错误异常
    print("值错误")

3. else clause
   In addition to try and except code blocks, we can also use else clauses. If the code in the try block does not raise any exception, the code in the else clause will be executed.

Code example:

try:
    # 可能会引发异常的代码
    result = 10 / 5
except ZeroDivisionError:
    # 处理除零异常
    print("除零错误")
else:
    # 无异常时执行的代码
    print("计算结果：", result)

4. finally clause
   The code in the finally clause will be executed regardless of whether an exception occurs in the try code block. Typically, resources or cleanup work are released in the finally clause.

Code sample:

try:
    # 可能会引发异常的代码
    result = 10 / 5
except ZeroDivisionError:
    # 处理除零异常
    print("除零错误")
else:
    # 无异常时执行的代码
    print("计算结果：", result)
finally:
    # 释放资源或清理工作
    print("程序结束")

5. Custom exception
   In addition to the built-in exception types, we can also customize exception types to better handle specific situations The following exception. We can create custom exception types by inheriting the Exception class.

Code sample:

class MyException(Exception):
    def __init__(self, message):
        self.message = message

try:
    # 可能会引发异常的代码
    raise MyException("自定义异常")
except MyException as e:
    # 处理自定义异常
    print(e.message)

By using these exception handling techniques appropriately, we can make our Python programs more robust and reliable. Whether it is handling expected exceptions or catching unexpected exceptions, it can improve the stability of our code. At the same time, adding appropriate exception handling to the code can better prompt error messages, making it easier for us to debug the code and locate the problem.

Given that Python's exception handling mechanism is very powerful and flexible, we should make full use of it when writing code to improve the quality and maintainability of our programs.

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