This post explains how to add to a dictionary in Python, create new dictionaries, and more. Powerful data manipulation is now within your grasp!

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。

The core of the Python data model architecture is the special methods (also known as 'magic methods'). These methods, which ...

From a powerful new assignment syntax to under-the-hood overhauls, Python 3.8 steps toward a more modern Python codebase Python 3.8 is the latest version of the popular language for everything ...

The dictionary functions in a similar fashion to the Python list, in that it is a collection of data. In this case, however, dictionaries hold key-value pairs instead of single values.