Hands-On Software Engineering with Python

Data access design strategies

The last bit of analysis that we need to undertake before we can start writing out the stories for this iteration involves determining where the responsibility for object data access is going to live. In a script or another purely procedural context, it would probably suffice to simply connect to a data source, read the data from it as needed, modify it as needed, and write any changes back out again, but that would only be viable because the entire procedure would be relatively static.

In an application or service such as hms_sys, data use is very much a random-access scenario—there may be common procedures that might even look a lot like a simple script's step-by-step implementations, but those processes could ...