File Handling in Python | Text Files | Class 12 Computer Science
Table of Contents
Introduction
This tutorial covers file handling in Python, focusing on text files, as outlined in the video by Swati Chawla. Understanding file handling is crucial for managing data efficiently in your Python applications, whether for reading, writing, or modifying text files.
Step 1: Understanding the Need for File Handling
File handling is essential for the following reasons:
- Data Persistence: Saving data beyond the runtime of a program.
- Data Management: Easy retrieval and storage of data.
- Data Sharing: Facilitating data exchange between different programs or users.
Step 2: Types of Files
Familiarize yourself with the main types of files in Python:
- Text Files: Store data in plain text format (e.g.,
.txt
files). - Binary Files: Store data in binary format (e.g., images, executables).
Step 3: Opening a File
To work with files, you first need to open them using Python's built-in open()
function. Here’s how:
- Use the following syntax:
file = open('filename.txt', 'mode')
- Replace
'filename.txt'
with your file name andmode
with the desired access mode.
Step 4: File Access Modes
Understand the different modes for opening files:
- 'r': Read mode (default).
- 'w': Write mode (overwrites existing data).
- 'a': Append mode (adds data without deleting existing content).
- 'b': Binary mode (used for binary files).
Step 5: Writing Data to a Text File
To write data into a text file:
- Open the file in write or append mode.
- Use the
write()
orwritelines()
method to add content.
Example:
with open('example.txt', 'w') as file:
file.write('Hello, World!\n')
file.writelines(['Line 1\n', 'Line 2\n'])
Step 6: Flushing the Buffer
When writing data, you may want to ensure that all data is written from the buffer to the file immediately. Use the flush()
method:
file.flush()
This is useful when you need to ensure data integrity before closing the file.
Step 7: Reading Data from a Text File
To read data from a text file:
- Open the file in read mode.
- Use methods like
read()
,readline()
, orreadlines()
.
Example:
with open('example.txt', 'r') as file:
content = file.read()
print(content)
Step 8: Closing the File
Always close the file after operations to free up system resources. Use:
file.close()
Alternatively, use the with
statement, which automatically handles closing the file.
Conclusion
In this tutorial, you learned about file handling in Python, including the need for it, different file types, how to open files, access modes, writing and reading data, and the importance of closing files. Mastering these skills will enhance your ability to manage data in your Python applications effectively. Next, consider practicing by creating your own text files and manipulating their contents using the techniques learned here.