5 Powerful Python one-liners

Rafael Zimmermann
CodeX
Published in
2 min readMar 31, 2022

Python one-liners can be just as powerful as a long and tedious program written in another language designed to do the same thing. In other languages this would be nearly impossible, but in Python, it’s a lot easier to do. The trick is to think of something that will “do a lot with a little.” Most importantly, reading and writing about Python one-liners (e.g., in this post) is a lot of fun! There’s even a whole subculture around who can write the shortest code for a given problem.

1. Share your Wi-Fi password with your guests by printing it as qr code

echo "WIFI:T:WPA;S:NETWORK_NAME;P:PASSWORD_HERE;H:;" | qr --output=wifi.png

To run this command you need to install two dependencies:

pip install pillow and pip install qrcode

2. CSV to JSON

python -c "import csv,json;print json.dumps(list(csv.reader(open('csv_file.csv'))))"

3. Apply regular expression to lines from stdin

[another command] | python -c "import sys,re;[sys.stdout.write(re.sub('PATTERN', 'SUBSTITUTION', line)) for line in sys.stdin]"

OK, this one there are other tools that can accomplish the same with a shorter command. But what I like about it is that is less likely to face incompatibility, as for instance sed, that might have different implementations across Linux and Mac.

4. Profile a python script

python -m cProfile foo.py

Check out how to use it here.

5. Start a Webserver on your current directory

$ python -m SimpleHTTPServer 8000

or on python3

$ python -m http.server

I used a lot in the past to share files between to machines inside the same network.

Do you know other useful one-liners, please share in the comments.

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Rafael Zimmermann
CodeX
Writer for

Father and Software developer. Interests: Java, Python, Ruby, Kafka, Kubernetes, Docker, AWS, GCP, etc.