How can I open multiple files using "with open" in Python?

Handling errors: Expect the unexpected

Entering the world of file management, you'll encounter quirks. Failing to open files due to a missing file or permissions issue can put a wrench in your gears. But ExitStack elegantly handles exceptions ensuring all previously opened files are closed. To be on the safe side, encapsulate your action with try-except blocks:

from contextlib import ExitStack

try:
    with ExitStack() as stack:
        files = [stack.enter_context(open(f)) for f in ['file1.txt', 'file2.txt', 'nonexistent.txt']]
        # Unleash your wizardry with the files
except IOError as e:
    print(f"We've hit an obstacle: {e}")


This elegant checkmark allows your script a chance to dance around real-world file system hurdles.

A sequential dance of the files

When managing numerous resources, it's tempting to open all files at once. However, processing files sequentially is a more resource-effective stratagem, especially for large or high-volume files. This method gently sips system file handles and memory. Try this shuffle:

filenames = ['file1.txt', 'file2.txt', 'file3.txt']
for filename in filenames:
    with open(filename) as file:
        # Here's your tango with each file


It might not provide the thrill of concurrency that ExitStack offers, but ensures a scalable solution that takes your code to the ball.

Your error handlers, your knight in shining armor

Navigating around issues like missing files or access denial makes your file handling code resilient! Robust error handling adds a layer of maintainability. Let's sneak in a peek into our weaponised toolbox:

try:
    with open('file1.txt') as file1, open('missing_file.txt') as file2:
        # Let the magic happen!
except FileNotFoundError as fnf_error:
    print(f"One file played hide and seek and lost: {fnf_error}")
except IOError as io_error:
    print(f"The file threw a tantrum: {io_error}")


This visualizes our proactive and reactive defense strategy, fending off any potential bugs.

Graceful syntax for concurrent operation

Python's syntax is the master key to efficient and effective concurrent operations. In Python 3.10+, parentheses in with statements treat you with simultaneous file management that is easy on the eyes:

with (
    open('file1.txt') as file1,
    open('file2.txt') as file2,
    open('file3.txt') as file3
):
    # All files at your command, Sire!


This syntax keeps your code looking like a haiku, complying with the Python Style Guide's stress on short and sweet lines.