33 Essential Python CLI Tricks You Should Bookmark

Today I compiled 33 useful Python command‑line tricks. Save them for quick reference.

1. Run Python code without a file

You can execute Python commands directly from the terminal without creating a script file:

<code>python -c "print('kiran')"</code>

2. Use Python as a calculator

Run quick calculations from the command line:

<code>python -c "print(5 * 4 + 100)"</code>

3. Debug with the -i flag

Keep the interpreter open after a script finishes to inspect variables:

<code>python -i my_script.py</code>

4. Get help for any module

Show a module’s documentation from the command line:

<code>python -c "help('math')"</code>

5. Measure code execution time

Use the -m timeit module to benchmark snippets:

<code>python -m timeit "y = [x**2 for x in range(2000)]"</code>

6. Quiet interactive mode with -q

Suppress the startup banner:

<code>python -q</code>

7. List all installed modules

Show every package installed in the current environment:

<code>python -m pip list</code>

8. Run a module directly

Execute a module without a script file, e.g., start a simple HTTP server:

<code>python -m http.server</code>

9. Generate a random number

Use the random module inline:

<code>python -c "import random; print(random.randint(1, 1000))"</code>

10. Check the Python version

<code>python --version</code>

11. Activate a virtual environment

<code>source venv/bin/activate</code>

12. Pretty‑print JSON files

<code>python -m json.tool < input.json > output.json</code>

13. Compress files with gzip

<code>python -c "import gzip, shutil; shutil.copyfileobj(open('file.txt','rb'), gzip.open('file.txt.gz','wb'))"</code>

14. Extract ZIP archives

<code>python -m zipfile -e my_file.zip ./output_folder</code>

15. Generate a quick password

<code>python -c "import secrets; print(secrets.token_urlsafe(16))"</code>

16. Check syntax without running code

<code>python -m py_compile my_script.py</code>

17. Count lines in a file

<code>python -c "print(len(open('file.txt').readlines()))"</code>

18. Test for primality

<code>python -c "print(all(101 % i != 0 for i in range(2, int(101**0.5)+1)))"</code>

19. Launch the REPL anywhere

<code>python</code>

20. Read a CSV file

<code>python -c "import csv; print(list(csv.reader(open('my_file.csv'))))"</code>

21. Sort a file alphabetically

<code>python -c "print(sorted(open('my_file.txt').readlines()))"</code>

22. Send a quick HTTP GET request

<code>python -c "import requests; print(requests.get('https://google.com').text)"</code>

23. Monitor a script’s memory usage

<code>python -m tracemalloc my_script.py</code>

24. Show the current time

<code>python -c "import time; print(time.ctime())"</code>

25. Simulate a dice roll

<code>python -c "import random; print(random.randint(1, 6))"</code>

26. Convert Celsius to Fahrenheit

<code>python -c "c=30; print(f'{c}C = {(c * 9/5) + 32}F')"</code>

27. Create a progress bar

<code>python -c "import time; [print(f'\r{i}%', end='') or time.sleep(0.1) for i in range(101)]"</code>

28. Generate a QR code

<code>python -c "import qrcode; qrcode.make('https://google.com').save('qrcode.png')"</code>

29. Send an email

<code>python -c "import smtplib; s = smtplib.SMTP('smtp.gmail.com', 587); s.starttls(); s.login('your_email', 'your_password'); s.sendmail('from', 'to', 'message'); s.quit()"</code>

30. Compute a factorial

<code>python -c "import math; print(math.factorial(5))"</code>

31. Plot a quick chart

<code>python -c "import matplotlib.pyplot as plt; plt.plot([1,2,3],[4,5,6]); plt.show()"</code>

32. Search for files

<code>python -c "import glob; print(glob.glob('*.txt'))"</code>

33. Check network speed

<code>python -c</code>