.python: Version

If you want to know which version of Python is currently active on your system, use the command line interface (CLI).

Standard Command:

python --version
# OR
python -V

If you have multiple versions installed (e.g., Python 2 and 3):

python2 --version
python3 --version

Expected Output:

Python 3.11.4

When selecting a Python version for a project, consider the following factors:

Python 2 was a monster success. It powered early Google, YouTube, Dropbox, and countless scientific projects. It was the language that taught a generation how to code.

But Python 2 had a curse:

print "hello" (no parentheses)
range(5) actually made a list of 5 numbers (wasteful!)
Unicode and text handling? A nightmare of u"text" and str vs unicode.

Python 2.7 (released 2010) was the "perfect" Python 2. And then… it stopped. The Python community set a date: January 1, 2020 – Python 2 dies.

That deadline became legend. Companies scrambled. "Python 2 to 3" conversion tools became heroes. And on that day? Python 2 was done – no more security patches, no more love. .python version

Some legacy systems still run Python 2. They’re like time capsules. Don’t open them.

Heroku has used a runtime.txt file for years, but as of 2023, they also support .python-version. Create the file and commit it:

python-3.11.5

Note: Heroku requires the python- prefix on the version string. If you want to know which version of

You might wonder, “Why can’t I just use whatever Python is on my PATH?”

Here are three scenarios that will convince you otherwise: