How to write a single line in text file using Python?

Python provides built-in capabilities for file creation, writing, and reading. You can handle both text files and binary files in Python. This article demonstrates how to write a single line to a text file using different modes.

To write to a file, first open it using the open() function, then use the write() method to save text. The file mode determines where the text will be placed ?

• "w" − Write mode clears the file content and writes at the beginning

• "a" − Append mode adds text at the end without clearing existing content

Syntax

file = open("filename.txt", "mode")
file.write("text content")
file.close()

Writing in Write Mode

Write mode ("w") creates a new file or overwrites existing content ?

# Open file in write mode
file = open('example.txt', 'w')
file.write("Hello, World!")
file.close()

# Read and display the content
with open('example.txt', 'r') as f:
    content = f.read()
    print("File content:", content)

File content: Hello, World!

Writing in Append Mode

Append mode ("a") adds text to the end of existing content without clearing it ?

# First, create a file with some content
with open('example.txt', 'w') as f:
    f.write("First line\n")

# Now append new content
file = open('example.txt', 'a')
file.write("Second line")
file.close()

# Read and display all content
with open('example.txt', 'r') as f:
    content = f.read()
    print("File content:")
    print(content)

File content:
First line
Second line

Using Context Manager (Recommended)

The with statement automatically handles file closing, even if errors occur ?

# Write using context manager
with open('example.txt', 'w') as file:
    file.write("This is a single line written safely!")

# Read to verify
with open('example.txt', 'r') as file:
    content = file.read()
    print("Content:", content)

Content: This is a single line written safely!

Comparison of Methods

Conclusion

Use "w" mode to overwrite files and "a" mode to append content. Always use the with statement for automatic file handling and better resource management.