Better illustration of Closures?

Question

I am learning Python using Dive Into Python 3 book. I like it, but I don\'t understand the example used to introduce Closures in Section 6.5.

I mean, I see how it wo

Answer 1

This might not seem particularly useful when you have access to the entire code base or when you do not have reusability in mind, but it is incredibly powerful and useful when trying to separate out logic into different, reusable modules that can be implemented in parallel by different developers. If you were to simply read the pattern strings from the file, every single module would have to be aware of this file and pass around that annoying list of pattern strings. And if you changed your system so that the pattern strings came from a URL instead of from a file, it could completely break your entire codebase. On the other hand, if you processing logic simply takes a callback function or several call back functions, and then you have another module that constructs the functions dynamically using content from a file, then only the component that constructs the functions needs to change. That is the power of being able to create functions dynamically.