Python File Handling Operations Overview

File Handling in Python

File handling refers to the operation performed on storing and retrieving data in various forms into files. It helps manage information effectively for further processing. Python offers several built-in functions to handle different types of files like Text, Binary, and CSV files. This article focuses on understanding file handling in Python within the context of the Computer Science curriculum for Class 12.

Text File Operations

A text file is used to store plain text data. Python provides several functions to perform operations on text files:

• open(): This function opens a text file with specific mode options for writing ('w'), appending ('a'), reading ('r'), etc.

f = open('example.txt', 'w')
f.write('Hello World!') # Writing to the file
f.close()

• read(), readline(), readlines(): These functions allow you to read the contents of a text file.

f = open('example.txt', 'r')
print(f.read())
print(f.readline())
print(f.readlines())
f.close()

• write(), writelines(): These functions are used to write data after opening the file in write mode.

f = open('example.txt', 'w')
f.write('Hello World!') # Writing to the file
f.write('\nWelcome!')
f.writelines(['Line1\n', 'Line2\n'])
f.close()

• seek(), tell(): These functions help move the cursor (position) inside the file.

f = open('example.txt', 'r')
f.seek(0)
print(f.tell())
f.close()

Binary File Operations

Binary files are used when the data needs to be stored in a particular format. The main difference between text and binary files lies in how the data is stored and accessed. Python provides similar functions for binary file operations as text files. However, the 'b' flag is added to specify binary mode.

f = open('example.bin', 'wb')
f.write(b'Hello World!') # Writing to the file
f.close()

• import pickle: Pickle is a module in Python which allows data to be serialized into bytes and vice versa. It is often used for saving complex Python objects in a file.

import pickle
data = {'Name': 'John', 'Age': 24}
f = open('example.dat', 'wb')
pickle.dump(data, f) # Serializing data to a file
f.close()

To read binary data, read(), readline(), readlines() are replaced with read().

CSV File Operations

CSV (Comma Separated Values) files are commonly used for storing data with columns separated by commas or other delimiters. Python provides functions to read and write CSV files using the built-in csv module.

import csv
data = {'Name': 'John', 'Age': 24}
f = open('example.csv', 'w')
writer = csv.DictWriter(f, fieldnames=['Name', 'Age'])
writer.writeheader() # Writing header
writer.writerow(data) # Writing data
writer.close()

To read CSV data, similar operations can be performed on the same file handle.

In conclusion, Python offers comprehensive support for handling different types of files through its built-in modules. This flexibility makes it an ideal choice for various applications requiring efficient data storage and retrieval.