Data is very important. Every organization depends on its data for continuing its business operations. If the data is lost, the organization has to be closed. This is the reason computers are primarily created for handling data, especially for storing and retrieving data. In later days, programs are developed to process the data that is stored in the computer.
To store data in a computer, we need files. For example, we can store employee data like employee number, name and salary in a file in the computer and later use it whenever we want. Similarly, we can store student data like student roll number, name and marks in the computer. In computer's view, a file is nothing but collection of data that is available to a program. Once we store data in a computer file, we can retrieve it and use it depending on our requirements.
There are four important advantages of storing data in a file:
- When the data is stored in a file, it is stored permanently. This means that even though the computer is switched off, the data is not removed from the memory since the file is stored on hard disk or CD. This file data can be utilized later, whenever required.
- It is possible to update the file data. For example, we can add new data to the existing file, delete unnecessary data from the file and modify the available data of the file. This makes the file more useful.
- Once the data is stored in a file, the same data can be shared by various programs. For example, once employee data is stored in a file, it can be used in a program to calculate employee's net salaries or in another program to calculate income tax payable by the employees.
- Files are highly useful to store huge amount of data. For example, voter's list or census data. Types of Files in Python In Python, there are two types of files. They are:
- Text files
- Binary files
Text files store the data in the form of characters. For example, if we store employee name "Ganesh", it will be stored as 6 characters and the employee salary 8900.75 is stored as 7 characters. Normally, text files are used to store characters or strings.
Binary files store entire data in the form of bytes, i.e. a group of 8 bits each. Image files are generally available in .jpg, .gif or .png formats. We cannot use text files to store images as the images do not contain characters. On the other hand, images contain pixels which are minute dots with which the picture is composed of. Each pixel can be represented by a bit, i.e. either 1 or 0. Since these bits can be handled by binary files, we can say that they are highly suitable to store images.