Зміст курсу

Python Advanced Concepts

1. Modules and Imports

Python Project Structure Understanding Modules Import Statements Understanding Libraries in Python Exploring Standard Libraries Package Management

2. Error Handling

Basics of Error Handling Raising Exceptions Handling Code After Exceptions Using Assertions Best Practices in Exception Handling

3. File Handling

Introduction to File Handling Reading and Writing Files Advanced File Operations Working with File Paths Context Managers Custom Context Managers Handling Binary Files

4. Pytest Framework

Introduction to Testing in Python Pytest Framework Assert Statement Test Parametrization

5. Unittest Framework

Introduction to Unittest Assert Methods SetUp and TearDown Steps Mocking Technique Mocking in Details

6. Iterators and Generators

Python Iterables Understanding Iterators Lazy Evaluation Introduction to Generators Practical Examples of Generators

Best Practices in Exception Handling

The 'as' Keyword in Exceptions

The as keyword is used in exception handling to capture an instance of the exception. This is useful for obtaining more details about the error and can be particularly helpful for logging or responding to the error in a more informed way.


              1234
            
try:
    x = 10 / 0
except ZeroDivisionError as e:
    print(f"Caught an exception: {e}")

What is Traceback?

A traceback provides details about the actual path taken by the execution of a program up to the point where the exception occurred. It includes the function calls made in your program and the line numbers in your code files where these calls were made. Tracebacks are vital for debugging errors in development and production environments.

Good Practices in Exception Handling

1. Catching Too General Exceptions

Catching too general exceptions can obscure the root cause of errors, making debugging difficult and potentially masking other issues that require specific handling, thereby reducing the reliability and maintainability of the software.

2. Catch and Re-Raise Exception

If you need to perform an operation when an exception occurs but still want the exception to bubble up.

Note

The functions log_error(e) and print(e) both display the full traceback of an error, which can be helpful during development. However, in a production environment, showing complete tracebacks can expose the application to vulnerabilities, as they often contain sensitive information.

3. Exception Performance

Avoid overusing try-except blocks in your code, as excessive use can slow down your program. Only implement them when they serve a functional purpose. Using an if statement is generally faster and more efficient.

Завдання

Swipe to show code editor

Refactor the following Python script to improve its exception handling based on the best practices discussed.

The code includes a check to ensure the data list is not empty before proceeding, using a ValueError.
The refactored code catches specific exceptions (ZeroDivisionError, TypeError, IndexError) instead of using a blanket except clause.
Each exception type has a custom error message that provides more context about what went wrong.

Перейдіть на комп'ютер для реальної практикиПродовжуйте з того місця, де ви зупинились, використовуючи один з наведених нижче варіантів

Все було зрозуміло?

Дякуємо за ваш відгук!

Секція 2. Розділ 5