Learn Web Development with Python

Splitting a complex task

Functions are also very useful for splitting long or complex tasks into smaller ones. The end result is that the code benefits from it in several ways, for example, readability, testability, and reuse. To give you a simple example, imagine that you're preparing a report. Your code needs to fetch data from a data source, parse it, filter it, polish it, and then a whole series of algorithms needs to be run against it, in order to produce the results that will feed the Report class. It's not uncommon to read procedures like this that are just one big do_report(data_source) function. There are tens or hundreds of lines of code that end with return report.

These situations are slightly more common in scientific code, which ...