defaultdict的核心原理是它在初始化时接受一个工厂函数（factory function），这个函数用于生成默认值。当访问一个不存在的键时，defaultdict会调用这个工厂函数来生成默认值，并将其插入到字典中。这使得defaultdict在处理图算法、计数器等需要频繁检查键是否存在的场景时，比普通字典更加高效和简洁。

大家好，我是程序员晚枫，学习网站：www.python-office.com，专注于AI、Python自动化办公。[1]1. 概念与原理Python 是一种广泛使用的高级编程语言，以其简洁的语法和强大的功能而闻名。然而，对于初学者来说，Python ...

The simplest form of regression in Python is, well, simple linear regression. With simple linear regression, you're trying to ...

Another really important thing that you need to know about Python in Excel is that Microsoft has created a special Python function that is used for interacting with Excel data.

Python lets you set default values for function arguments, which is super convenient. But when those default values are mutable (like lists or dictionaries), you're walking into a sneaky bug trap.

The pattern-matching syntax introduced in Python 3.10 allows for powerful new programming techniques for decision-making in apps.

How to Build a Windows Search Function in Python. If you happen to not like the default Windows search options then you can write your own Windows search function in Python by following a few steps.

Learn how the new asynchronous standard for Python web applications makes apps faster, more flexible, and more future-proof.