File Handling with try...finally in Python

When working with files, we must always close the file to:

Free system resources
Avoid memory leaks
Prevent file corruption
Ensure data is written to disk

The finally block always executes, even if an error occurs.

Basic File Handling Without try...finally (Problem)

Python

file = open("data.txt", "r")
data = file.read()
print(data)
file.close()

Problem: If an error happens before file.close(), the file remains open.

File Handling with try...finally (Correct Way)

Python

try:
    # Open file in read mode
    file = open("data.txt", "r")

    # Read file content
    data = file.read()
    print(data)

finally:
    # This block ALWAYS runs (even if error occurs)
    file.close()
    print("File closed successfully")

Key Points

try → Code that may cause an error.
finally → Cleanup code that always executes.

Best Practice: Using with (Recommended Over try...finally)

Python provides a context manager that automatically closes files.

Python

with open("data.txt", "r") as file:
    data = file.read()
    print(data)

# No need to close file manually

Why with is Better

Cleaner and more readable syntax.
No risk of forgetting to close the file.
Automatically handles exceptions and cleanup.

Previous Next