File Handling in Python: Reading, Writing, and Managing Data

python dev.to June 04, 2026

Writing Files
Using open() with "w" mode, you can create or overwrite files. The with statement ensures files are closed properly.

filename = "sample.txt"

with open(filename, "w", encoding="utf-8") as file:
    file.write("Hello file handling!\n")
    file.write("This is a second line.\n")
print("Wrote to", filename)

Reading Files
open() with "r" mode lets you read files. read() loads the entire content, while iterating reads line by line.

with open(filename, "r", encoding="utf-8") as file:
    content = file.read()
print("File content:")
print(content)

Line‑by‑Line Reading
Reading files line by line is efficient for large files, as it avoids loading everything into memory at once.

with open(filename, "r", encoding="utf-8") as file:
    for line in file:
        print("Line:", line.strip())

My take
File handling allows Python to interact with the outside world. You can:

Write data to files for storage.
Read files to process information.
Handle files line by line for efficiency. This skill is essential for building applications that log activity, store user data, or process text files.

Source: dev.to