So far, we have learned how to write programs and communicate our intentions to the Central Processing Unit using conditional execution, functions, and iterations.
We have learned how to create and use data structures in theMainMemory.
The CPU and memory are where our software works and runs. It is where all of the “thinking” happens.
But if you recall from our hardware architecture discussions, once the power is turned off, anything stored in either the CPU or main memory is erased. So up to now, our programs have just been transient fun exercises to learn Python.
In this chapter, we start to work with Secondary Memory (or files). Secondary
memory is not erased even when the power is turned off. Or in the case of a USB
flash drive, the data can we write from our programs can be removed from the
system and transported to another system.
We will primarily focus on reading and writing text files such as those we create
in a text editor. Later we will see how to work with database files which are binary
files, specifically designed to be read and written through database software.