Python File Handling Notes – Class 12 CS (03) | CBSE Board Preparation
Full revision with this Python File Handling notes! Master text, binary, and CSV files easily with simple and to-the-point explanations and solved programs.
From the CBSE Class 12 Computer Science (Code 083) examination perspective, File Handling in Python is a highly important chapter and typically contributes around 10 marks in board examinations. The pattern of questions asked from this chapter remains quite similar every year, making it one of the most scoring topics. Therefore, students should practice this chapter thoroughly to ensure maximum marks in both theory and practical examinations.
In this chapter, we will learn about Text Files, Binary Files, and CSV (Comma Separated Values) Files, along with various operations that can be performed on them, such as creating, reading, writing, and appending data.
These File Handling in Python Notes bring together everything you need for board exams, practicals, and last-minute revision. Instead of wasting time searching through multiple textbooks, you can focus entirely on learning everything in one single place.
Introduction to Files
In the programs, data is stored in variables, which exist only while the program is running. Once the program ends, all the data stored in those variables is lost. To save data permanently and use it again in the future, we need files.
Files allow us to store information such as employee records, sales data, inventory details, and program output on secondary storage devices (such as hard disks or SSDs). Just as Python programs are saved as .py files, data can also be stored in files for later access and reuse.
Definition:
A file is a named location on a secondary storage device where data is stored permanently and can be accessed whenever required.
File Path – Absolute and Relative Path
A file path specifies the location of a file in the computer system. there are two ways for specify location:
- Absolute path
- Relative path
| Absolute Path | Relative Path |
| Complete path from root directory to the file | Path relative to current working directory |
| Does not depend on current directory | Depends on current working directory |
| Usually long and detailed | Short and simple |
| Starts from root (full location) | Starts from current location |
| Always points to same file location | May change if working directory changes |
| C:\Users\Student\Documents\myfile.txt | myfile.txt, data\myfile.txt |
Types of Files
There are three main types of files:
- Text Files (.txt): Storing plain, human-readable text.
- Binary Files (.dat): Handling raw byte data using the pickle module.
- CSV Files (.csv): Managing structured, tabular data.
Text File
- A text file is a sequence of characters including alphabets, numbers, and special symbols.
- Common examples of text files include files with extensions like .txt, .py, .csv, etc.
- Internally, the file is not stored as characters but as a sequence of bytes (0s and 1s).
- Each character is stored using encoding schemes like ASCII, Unicode, etc.
- While opening the file, the text editor converts these byte values into human-readable characters.
📘 Detailed Text File Notes Available
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Binary Files
- Binary files are stored as bytes (0s and 1s), but these bytes do not represent ASCII character values.
- Instead, they store actual data such as images, audio, video, compressed files, and executable files.
- Binary files are not human-readable.
- Opening a binary file in a text editor displays unreadable or garbage values.
- Special software is required to read or write binary file contents.
📘 Detailed Binary File Notes Available
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CSV Files
- CSV (Comma Separated Values) is a simple flat file format used to store tabular data.
- It stores numbers and text in plain text format, making it human readable.
- Commonly used for data sharing through spreadsheets and databases.
- Files can be imported/exported in applications like spreadsheets.
- Each record contains fields (values) separated by commas (delimiter).
- Comma is the most commonly used delimiter, but others like tab (\t), colon (:), and semicolon (;) can also be used.
📘 Detailed CSV File Notes Available
Learn CSV File Handling in detail with easy explanations, practical programs, and important CBSE board exam questions. Click here →
