Mobile Python: Rapid Prototyping of Applications on the Mobile Platform

Chapter 6. Data Handling

When building applications, sooner or later you will come to the point where you want to store some user settings, log data, videos, music, or image files to the phone. This chapter gives you an introduction to handling data like this. As you will see, PyS60 is quite flexible and easy to use in this regard.

Nowadays, data persistence is often handled on the server side. Think of Google GMail, Flickr or the contact list in Skype – all these services ensure that your information moves with you even though you may access the services from various physical devices. Backups, scalability and data aggregation are easier to handle on the server side than on a single small device. These viewpoints should encourage you to think about storing data in unorthodox ways when programming mobile applications with PyS60. In many cases, sending data to a server is easier than saving it locally.

In some cases, saving data locally is the only sensible option. You should be able to save photos, sounds or log events without a network connection. You may need a local configuration file to specify how to setup a network connection in the first place. And since mobile networks may be unreliable and often have low bandwidth, caching information locally can be vital.

This is where the lessons of this chapter prove useful. First, in Section 6.1, we explain where files can be loaded and saved on the S60 platform. We introduce the File object that handles reading and writing of files. ...