Python File Append

What is File Appending?

Appending a file means adding new data at the end of an existing file without deleting or overwriting the current content.

In Python, opening a file in append mode 'a' allows you to add new data at the file's end safely.

This is useful for logging, saving new entries, or adding incremental data without losing previous information.

फाइल में अपेंड करने का मतलब है मौजूदा फाइल के अंत में नया डेटा जोड़ना बिना पुराने डेटा को हटाए या बदलें।

Python में, फाइल को अपेंड मोड 'a' में खोलकर आप नई जानकारी फाइल के अंत में सुरक्षित रूप से जोड़ सकते हैं।

यह लॉगिंग, नए एंट्री जोड़ने, या डेटा को क्रमिक रूप से अपडेट करने के लिए उपयोगी होता है बिना पुराने डेटा खोए।

5 Examples of File Appending in Python

Example 1: Append a Single Line to a Text File

with open('log.txt', 'a') as file:
    file.write('New log entry\n')

Output:
Adds a new line 'New log entry' to the end of 'log.txt'.

This code opens 'log.txt' in append mode and writes a new line at the end.

Example 2: Append Multiple Lines Using writelines()

lines = ['First line\n', 'Second line\n', 'Third line\n']
with open('log.txt', 'a') as file:
    file.writelines(lines)

Output:
Adds three lines at the end of 'log.txt'.

writelines() appends multiple lines from a list to the file.

Example 3: Append Text with Encoding Specified

with open('log.txt', 'a', encoding='utf-8') as file:
    file.write('अपेंडिंग UTF-8 में\n')

Output:
Appends a UTF-8 encoded Hindi text line safely.

Specifying encoding ensures correct handling of non-ASCII characters during append.

Example 4: Appending Numbers Converted to String

with open('numbers.txt', 'a') as file:
    for i in range(1, 4):
        file.write(str(i) + '\n')

Output:
Appends numbers 1, 2, 3 each on a new line at the end of 'numbers.txt'.

Convert numbers to string before appending since file.write() accepts strings.

Example 5: Append User Input to a File

user_input = input('Enter a note to save: ')
with open('notes.txt', 'a') as file:
    file.write(user_input + '\n')

Output:
Appends user input text to 'notes.txt'.

User input is taken and appended to the file as a new line.