Which python version linux

How to select which version of python I am running on Linux?

The version of Linux I am working on has python 2.6 by default, and we installed 2.7 on it in a separate folder.

If I want to run a .py script, how do I tell it to use 2.7 instead of the default?

4 Answers 4

Use update-alternatives —config python and shoose python2.7 from choices.
If you need to remove it use update-alternatives —remove python /usr/bin/python2.7 .

Sorry for «stealing» answers, but I feel that there is a little bit of chaos here.

There are different ways to achieve that, it depends on at what level the decision is taken.

System Level

Use the update-alternatives feature of the system. Specifically, use

and you can choose the specific version.

Result: Once you do this, everything that uses » python » will use the python2.7 binary. This will happen in the whole system, for all users.

User Level

This is a little bit trickier. Credit to @TheFlyingProgrammer

The basic approach would be to change the .bashrc file in order to change the path and/or add an alias. Problem is if you are relying on the «shebang» of the file:

This kind of file will be unaffected of your changes. However:

or executions like

will use the interpreter of choice (the one forced at the .bashrc file).

Result: The owner of the modified .bashrc file will use, by default, the interpreter of choice. But some sheband will behave differently. So it is a bit trickier. So, be cautious.

Script Level

[Credit to @Anony-Mousse]

The «shebang» approach, modifying the first line. The idea is using the full path in the first line of the python source file:

You can use python , python2 or python2.7 and you will be more or less specific in the version. The problem would be if you want it to be portable. A similar approach would be to use full specification of version but without path:

Note that if the PATH is not correctly set, this won’t work. This gives some power to the user (when setting the PATH ). You can, for instance, choose #!/usr/bin/env python2 to force some Python 2.x flavour, but maybe the specific binary will change from user to user.

In addition to that, keep in mind that if you plan to use virtual environments, using /usr/bin/env python is advisable (if I’m not mistaken).

Result: Well, it depends whether you use the env binary or not. But, in any case, you are putting the semantic in the file, which makes sense in many cases (e.g. if there is an incompatibility, it is at the script level).

Execution Level

[Credit to @Prune]

This is the simplest approach:

You change, for this specific execution, which binary will be using (the Python interpreter ignores the shebang, because it is a comment).

Result: You override all other choices by cherry-picking your Python binary. Very good approach to test behaviour, but not very maintainable or shareable.

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How to Check Python Version in Linux, Mac, & Windows

Home » SysAdmin » How to Check Python Version in Linux, Mac, & Windows

Which version of Python do I have installed?

Python is a popular programming language. Like many other programming languages, there can be several different versions organized by release date. Certain applications may require a specific version of Python.

In this tutorial, learn how to check the Python version on Windows, Linux, or macOS systems.

Access to a command-line/terminal window:

• Linux: Ctrl-Alt-T, Ctrl-Alt-F2
• Windows: Win+R > type powershell > Enter/OK
• MacOS: Finder > Applications > Utilities > Terminal

There are different versions of Python, but the two most popular ones are Python 2.7.x and Python 3.7.x. The x stands for the revision level and could change as new releases come out.

When looking at the version number, there are usually three digits to read:

1. the major version
2. the minor version
3. the micro version

While major releases are not fully compatible, minor releases generally are. Version 3.6.1 should be compatible with 3.7.1 for example. The final digit signifies the latest patches and updates.

Python 2.7 and 3.7 are different applications. Software that’s written in one version often will not work correctly in another version. When using Python, it is essential to know which version an application requires, and which version you have.

Python 2 will stop publishing security updates and patches after 2020. They extended the deadline because of the large number of developers using Python 2.7. Python 3 includes a 2 to 3 utility that helps translate Python 2 code into Python 3.

How to Check Python Version in Linux

Most modern Linux distributions come with Python pre-installed.

To check the version installed, open a terminal window and entering the following:

How to Check Python Version in Windows

Most out-of-the-box Windows installations do not come with Python pre-installed. However, it is always a good idea to check.

Open Windows Powershell, and enter the following:

If you have Python installed, it will report the version number.

Alternately, use the Windows Search function to see which version of Python you have:

Press the Windows key to start a search, then type Python. The system will return any results that match. Most likely a match will show something similar to:

This defines which major and minor revision (3.x or 2.x) you are using.

How to Check Python Version in MacOS

If using a MacOS, check the Python version by entering the following command in the terminal:

The system will report the version.

Note: In some cases, this will return a screen full of information. If that happens, just scan through the file locations for the word python with a number after it. That number is the version.

Checking a System with Multiple Versions of Python

Python2 and Python3 are different programs. Many programs upgrade from the older version to the newer one. However, Python 2.7.x installations can be run separately from the Python 3.7.x version on the same system.

Python 3 is not entirely backward compatible.

To check for Python 2.7.x:

To check the version of Python 3 software:

Most systems differentiate Python 2 as python and Python 3 as python3. If you do not have Python 2, your system may use the python command in place of python3 .

Note: Python does not have a built-in upgrade system. You’ll need to download the latest version and install it.

How to Check Python Version in Script

When writing an application, it is helpful to have the software check the version of Python before it runs to prevent crashes and incompatibilities.

Use the following code snippet to check for the correct version of Python:

When this script runs, it will test to see if Python 3.6 is installed on the system. If not, it will send a notification and displays the current Python version.

Note: One of the common issues in working with Python and datasets is missing data. Learn how to handle missing data in Python.

You should now have a solid understanding of how to check for the version of Python installed in several different operating systems. Python is a powerful programming language, thus it’s important to understand its different versions.

If you want to learn how to upgrade Python to a newer version on Wondows, macOs, and Linux, check our article how to upgrade Python to 3.9.

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Which version of Python do I have installed?

I have to run a Python script on a Windows server. How can I know which version of Python I have, and does it even really matter?

I was thinking of updating to the latest version of Python.

23 Answers 23

—version may also work (introduced in version 2.5)

In a Python IDE, just copy and paste in the following code and run it (the version will come up in the output area):

At a command prompt type:

Or if you have pyenv:

Although the question is «which version am I using?», this may not actually be everything you need to know. You may have other versions installed and this can cause problems, particularly when installing additional modules. This is my rough-and-ready approach to finding out what versions are installed:

The output for a single Python installation should look something like this:

Multiple installations will have output something like this:

When I open Python (command line) the first thing it tells me is the version.

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HOW TO CHECK YOUR PYTHON VERSION

To check your Python version, run python —version in your command line (Windows), shell (Mac), or terminal (Linux/Ubuntu). To check your Python version in your script, run import sys to get the module and use sys.version to find detailed version information in your code.

Let’s get a quick overview of the different ways to check your Python version in all operating systems and environments. This may be all you need to know:

Commands	Where?	What?	Example Output
python —version or python -V or python -VV	Terminal	Mac/Linux/Win	Python 3.7.2
import sys sys.version	Python Script	Information string	‘3.7.2 (tags/v3.7.2:9a3ffc0492, Dec 23 2018, 23:09:28) [MSC v.1916 64 bit (AMD64)]’
sys.version_info	Python script	Version info tuple	sys.version_info(major=3, minor=7, micro=2, releaselevel=’final’, serial=0)
import platform platform.python_version()	Python script	Short string info	‘3.7.2’
platform.python_version_tuple()	Python script	Short tuple info	(‘3’, ‘7’, ‘2’)

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Table of Contents

Overview

When Guido van Rossum released the first viable Python version 0.9.0 in 1991, he couldn’t have expected (by a long shot) that he was on the verge of creating the most influential programming language in the world. Python has a bright future: every new Python version adds new features to the programming language.

In the following video and blog tutorial, I’ll show you how to check your Python version—no matter your operating system (Windows, macOS, Linux, Ubuntu) and programming framework (Jupyter). You can play the video while you scroll down to read the step-by-step instructions on how to check your Python version.

If you’re like me ten years ago, you need to Google important Python commands again and again. Fortunately, I found a simple and effective (and free) way to improve my Python skills. And so can you: learning with cheat sheets.

Join my email academy and download your free Python cheat sheets about various topics such as keywords, object-orientation, NumPy, and data structures.

Environments

This general method works across all major operating systems (Windows, Linux, and macOS).

OS & Environment	Method
Win10, Win7	Open command line and run python -V or python —version
MacOS, Linux, Ubuntu	Open terminal and run python -V or python —version
Python Shell, Juypter Notebook	Interactive mode: >>> import sys >>> sys.version
Python Editor, Juypter Notebook	Normal mode: import sys print(sys.version)

The table shows you how different environments call for different commands to check your Python version. You may have the following question:

How to open your command line or terminal?

• Windows: Hit shortcut Win+R , type powershell , hit OK .
• MacOS: Hit shortcut Cmd+Space , type terminal , hit OK .
• Linux: Hit shortcut Ctrl+Alt+T .

The Python version output consists of three numbers major:minor:micro. For example, version 3.7.2 means that

• the major version is 3,
• the minor version is 7, and
• the micro version is 2.

[ATTENTION] Different major versions are NOT fully compatible. Different minor versions are compatible.

For example, you can execute code written in Python 3.6.4 in Python 3.7.2 because they are the same major version — Python 3. But you cannot execute code written in Python 2.7.4 in Python 3.7.2 because they are different major versions.

Note that new minor versions can add changes to the language. For example, in Python 3.8 they introduced the reversed() function with dictionaries. You cannot use the reversed() function in older versions of Python. But the vast majority of the language is the same.

Before you move on to the exact steps you need to perform on your exact environment, please allow me to quickly present you my book “Coffee Break Python“. It uses the powerful puzzle-based learning method that helps you boost your rapid code understanding skills in Python.

Science shows that puzzle-based learning and practice testing improves learning retention by 44%.

Here’s an Amazon review of the book:

Feel free to check out the book if you’re an ambitious Python student and you want to reach advanced Python skill levels!

Let’s dive into the exact steps to check your Python version in any environment. I tried to figure out any environment you may be interested in. But if you don’t find yours, please let me know (chris at finxter dot com) and I’ll add your specific environment, too.

You can check out our interactive story to see how to check the Python version in different environments:

Click to move to next page!

Check Which Python Version in Script (Exact Steps)

Sometimes, you want to check Python’s version in your Python program.

To achieve this, simply import the sys module and print the sys.version attribute to your Python shell:

Check Python Version Jupyter (Exact Steps)

Three steps to check the Python version in a Jupyter notebook.

1. Open the Jupyter notebook: type jupyter notebook in your terminal/console.
2. Write the following Python code snippet in a code cell:

3. Execute the script.

As an alternative, you can also use the following Python code snippet to check your Python version in a Jupyter notebook:

Here is a screenshot on my computer:

Check Python Version Windows 10 (Exact Steps)

Three steps to check the Python version on your Win 10 operating system:

1. Open the Powershell application: Press the Windows key to open the start screen. In the search box, type “powershell”. Press enter.
2. Execute command : type python —version and press enter.
3. The Python version appears in the next line below your command.

Check Python Version Windows 7 (Exact Steps)

Three steps to check the Python version on your Win 7 operating system.

1. Open the command prompt application: Press the Windows key to open the start screen. In the search box type “command”. Click on the command prompt application.
2. Execute command : type python —version and press enter.
3. The Python version appears in the next line right below your command.

Check Python Version Mac (Exact Steps)

Four steps to check the Python version on your Mac operating system.

1. Press CMD + Space to open Spotlight.
2. Type “terminal” and press enter.
3. Execute command : type python —version or python -V and press enter.
4. The Python version appears in the next line below your command.

Check Python Version Linux (Exact Steps)

Three steps to check the Python version on your Linux operating system.

1. Open the terminal application (for example, bash).
2. Execute command : type in python —version or python -V and press enter.
3. The Python version appears in the next line below your command.

Check Python Version Ubuntu (Exact Steps)

Four steps to check the Python version on your Ubuntu operating system.

1. Open Dash: click the upper left symbol.
2. Open terminal: type “terminal”, click on the terminal app.
3. Execute command : type python —version or python -V and press enter.
4. The Python version appears in the next line right below your command.

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Check Your Python Version in Anaconda (Exact Steps)

You can choose from different alternatives.

• To check your Anaconda version, run conda -V or conda —version in your anaconda prompt. You can open the anaconda prompt by searching for “anaconda prompt” in your OS’s search field.
• An alternative to get your Anaconda version is to run conda list anaconda .
• The shorter command conda list lists the name, version, and build details of your installed packages.
• To learn about your environment details, run conda info with the optional flag –envs to see all your environments.
• To check your Python version, run python -V or python —version in your terminal.

Related Material: Please find more detailed information about setting up your environment here. You can download an informative Anaconda cheat sheet here.

Check Your Python Version in Spyder (Exact Steps)

In your Spyder code editor, it’s even simpler to check your Python version. Just run any script and the version information will appear in the first line before the output of your script.

[History] What are the Different Python Versions?

Python has three main versions: version 1, version 2, and version 3. Version 4 is currently (2020) under development.

Here is the version history from Wikipedia and the official docs.

Python 3.0 – December 3, 2008

• Python 3.8.2 ― released on 24 February 2020.
• Python 3.8.1 ― released on 18 December 2019.
• Python 3.8.0 ― released on 14 October 2019.
• Python 3.7.7 ― released on 10 March 2020.
• Python 3.7.6 ― released on 18 December 2019.
• Python 3.7.5 ― released on 15 October 2019.
• Python 3.7.4 ― released on 08 July 2019.
• Python 3.7.3 ― released on 25 March 2019.
• Python 3.7.2 ― released on 24 December 2018.
• Python 3.7.1 ― released on 20 October 2018.
• Python 3.7.0 ― released on 27 June 2018.
• Python 3.6.10 ― released on 18 December 2019.
• Python 3.6.9 ― released on 02 July 2019.
• Python 3.6.8 ― released on 24 December 2018.
• Python 3.6.7 ― released on 20 October 2018.
• Python 3.6.6 ― released on 27 June 2018.
• Python 3.6.5 ― released on 28 March 2018.
• Python 3.6.4 ― released on 19 December 2017.
• Python 3.6.3 ― released on 03 October 2017.
• Python 3.6.2 ― released on 17 July 2017.
• Python 3.6.1 ― released on 21 March 2017.
• Python 3.6.0 ― released on 23 December 2016.
• Python 3.5.8 ― released on 29 October 2019.
• Python 3.5.7 ― released on 18 March 2019.
• Python 3.5.6 ― released on 8 August 2018.
• Python 3.5.5 ― released on 4 February 2018.
• Python 3.5.4 ― released on 25 July 2017.
• Python 3.5.3 ― released on 17 January 2017.
• Python 3.5.2 ― released on 27 June 2016.
• Python 3.5.1 ― released on 07 December 2015.
• Python 3.5.0 ― released on 13 September 2015.
• Python 3.4.10 ― released on 18 March 2019.
• Python 3.4.9 ― released on 8 August 2018.
• Python 3.4.8 ― released on 4 February 2018.
• Python 3.4.7 ― released on 25 July 2017.
• Python 3.4.6 ― released on 17 January 2017.
• Python 3.4.5 ― released on 26 June 2016.
• Python 3.4.4 ― released on 06 December 2015.
• Python 3.4.3 ― released on 25 February 2015.
• Python 3.4.2 ― released on 4 October 2014.
• Python 3.4.1 ― released on 18 May 2014.
• Python 3.4.0 ― released on 16 March 2014.
• Python 3.3.7 ― released on 19 September 2017.
• Python 3.3.6 ― released on 12 October 2014.
• Python 3.3.5 ― released on 9 March 2014.
• Python 3.3.4 ― released on 9 February 2014.
• Python 3.3.3 ― released on 17 November 2013.
• Python 3.3.2 ― released on 15 May 2013.
• Python 3.3.1 ― released on 7 April 2013.
• Python 3.3.0 ― released on 29 September 2012.
• Python 3.2.6 ― released on 11 October 2014.
• Python 3.2.5 ― released on 15 May 2013.
• Python 3.2.4 ― released on 7 April 2013.
• Python 3.2.3 ― released on 10 April 2012.
• Python 3.2.2 ― released on 4 September 2011.
• Python 3.2.1 ― released on 10 July 2011.
• Python 3.2 ― released on 20 February 2011.
• Python 3.1.5 ― released on 9 April 2012.
• Python 3.1.4 ― released on 11 June 2011.
• Python 3.1.3 ― released on 27 November 2010.
• Python 3.1.2 ― released on 21 March 2010.
• Python 3.1.1 ― released on 17 August 2009.
• Python 3.1 ― released on 27 June 2009.
• Python 3.0.1 ― released on 13 February 2009.
• Python 3.0 ― released on 3 December 2008.

Python 2.0 – October 16, 2000

• Python 2.7.17 ― released on 19 October 2019
• Python 2.7.16 ― released on 02 March 2019
• Python 2.7.15 ― released on 30 April 2018
• Python 2.7.14 ― released on 16 September 2017
• Python 2.7.13 ― released on 17 December 2016
• Python 2.7.12 ― released on 26 June 2016.
• Python 2.7.11 ― released on 5 December 2015.
• Python 2.7.10 ― released on 23 May 2015.
• Python 2.7.9 ― released on 10 December 2014.
• Python 2.7.8 ― released on 1 July 2014.
• Python 2.7.7 ― released on 31 May 2014.
• Python 2.7.6 ― released on 10 November 2013.
• Python 2.7.5 ― released on 15 May 2013.
• Python 2.7.4 ― released on 6 April 2013.
• Python 2.7.3 ― released on 9 April 2012.
• Python 2.7.2 ― released on 11 June 2011.
• Python 2.7.1 ― released on 27 November 2010.
• Python 2.7 ― released on 4 July 2010.
• Python 2.6.9 ― released on 29 October 2013.
• Python 2.6.8 ― released on 10 April 2012.
• Python 2.6.7 ― released on 3 June 2011.
• Python 2.6.6 ― released on 24 August 2010.
• Python 2.6.5 ― released on 19 March 2010.
• Python 2.6.4 ― released on 25 October 2009.
• Python 2.6.3 ― released on 2 October 2009.
• Python 2.6.2 ― released on 14 April 2009.
• Python 2.6.1 ― released on 4 December 2008.
• Python 2.6 ― released on 1 October 2008.
• Python 2.5.4 ― released on 23 December 2008.
• Python 2.5.3 ― released on 19 December 2008.
• Python 2.5.2 ― released on 21 February 2008.
• Python 2.5.1 ― released on 18 April 2007.
• Python 2.5 ― released on 19 September 2006.
• Python 2.4.4 ― released on 18 October 2006.
• Python 2.4.3 ― released on 29 March 2006.
• Python 2.4.2 ― released on 28 September 2005.
• Python 2.4.1 ― released on 30 March 2005.
• Python 2.4 ― released on 30 November 2004.
• Python 2.3.5 ― released on 8 February 2005.
• Python 2.3.4 ― released on 27 May 2004.
• Python 2.3.3 ― released on 19 December 2003.
• Python 2.3.2 ― released on 3 October 2003.
• Python 2.3.1 ― released on 23 September 2003.
• Python 2.3 ― released on 29 July 2003.
• Python 2.2.3 ― released on 30 May 2003.
• Python 2.2.2 ― released on 14 October 2002.
• Python 2.2.1 ― released on 10 April 2002.
• Python 2.2p1 ― released on 29 March 2002.
• Python 2.2 ― released on 21 December 2001.
• Python 2.1.3 ― released on 8 April 2002.
• Python 2.1.2 ― released on 16 January 2002.
• Python 2.1.1 ― released on 20 July 2001.
• Python 2.1 ― released on 15 April 2001.
• Python 2.0.1 ― released on 22 June 2001.
• Python 2.0 ― released on 16 October 2000.

Python 1.0 – January 1994

• Python 1.6 ― released on 5 September 2000.
• Python 1.5.2p2 ― released on 22 March 2000.
• Python 1.5.2p1 ― released on 6 July 1999.
• Python 1.5.2 ― released on 30 April 1999.
• Python 1.5.1p1 ― released on 6 August 1998.
• Python 1.5.1 ― released on 14 April 1998.
• Python 1.5 ― released on 17 February 1998.
• Python 1.4 ― released on 25 October 1996.

Python 0.9.0 – February 20, 1991

• Python 0.9.1 ― released on February 1991
• Python 0.9.2 ― released on Autumn, 1991
• Python 0.9.4 ― released on December 24, 1991
• Python 0.9.5 ― released on January 2, 1992
• Python 0.9.6 ― released on April 6, 1992
• Python 0.9.8 ― released on January 9, 1993
• Python 0.9.9 ― released on July 29, 1993

As there are some significant differences in syntax, you should always install the latest version in Python. Keep yourself updated on the official Python website here.

How to Upgrade to a Newer Version?

If you are not using a virtual environment, go to python.org/downloads to download and install whatever version you need. It’s the easiest way to upgrade Python.

But now you’ll run into the following problem: how do I run a specific Python version? Check out this StackOverflow answer to learn the exact steps.

Or you can make your life easier by using virtual environments. These let you have multiple versions of Python installed on your system. Plus, you can switch between them instantaneously. One option is to use the built-in module venv. If you’re a Data Scientist, the industry standard is Anaconda.

Installing and upgrading different Python versions is easy when you use virtual environments. For a full tutorial of virtual environments, read over our introductory Finxter blog article.

How to Check if Python 3 is Installed?

If you’ve installed multiple installations of Python, running python —version may give you only the version of Python 2. To check which version of Python 3 is installed on your computer, simply run the command python3 —version instead of python —version .

How to Check Python Version – Detailed

Not only does Python have major, minor and micro versions. Each of those versions has further versions, namely the release level and serial.

These are displayed when you run

In the above code, I am running Python 3.8.0.

Most of the time, you will only care about the major, minor and micro releases. Release level and serial are usually for the core Python Dev team to work on changes to the language.

The possible release levels are ‘alpha’, ‘beta’, ‘candidate’, or ‘final’. Alpha contains the first updates made to the language. Beta means the language can be tested with some users but still won’t work perfectly. This is where the phrase ‘beta testers’ comes from. A ‘candidate’ has only a few small bugs left to fix. Final is the last version and the one released to the general public. If you want to try out new features before anyone else, you can download these release levels. However, if you just want a version of Python that works, you should choose ‘final’. When you download any version of Python, it will be a ‘final’ release unless stated otherwise.

Serial is for the smallest changes. The Python Dev team increments it as they make changes to the alpha, beta and candidate versions. All final versions have serial=0. They add future changes to the next major/minor/micro releases.

How to Make Sure My Script Runs a Specific Python Version?

Let’s say you’ve just installed Python 3.8. Your script, my_file.py , uses a brand new feature: reversed() when iterating over a dictionary. For other people to run this script, they must also run Python 3.8. So you should put a check at the start to let other users know this.

We do this by adding an assert statement at the top of my_file.py

The assert statement raises an AssertionError if the statement is False. If the statement is True, the script continues to run.

For example, if I am running Python 3.7 and execute my_file.py from the terminal, this happens

But if I am running Python 3.8, the assert statement does not raise an error, and it executes the rest of the script.

Note: I have used the Anaconda virtual environment to install and quickly switch between multiple Python versions.

Summary

Check the Python version by typing python —version in your operating system shell or command line. To get more detailed information about the environment your Python program runs in, try import sys; sys.version in your Python shell (interactive or normal mode).

Where to Go From Here?

Enough theory, let’s get some practice!

To become successful in coding, you need to get out there and solve real problems for real people. That’s how you can become a six-figure earner easily. And that’s how you polish the skills you really need in practice. After all, what’s the use of learning theory that nobody ever needs?

Practice projects is how you sharpen your saw in coding!

Do you want to become a code master by focusing on practical code projects that actually earn you money and solve problems for people?

Then become a Python freelance developer! It’s the best way of approaching the task of improving your Python skills—even if you are a complete beginner.

Join my free webinar “How to Build Your High-Income Skill Python” and watch how I grew my coding business online and how you can, too—from the comfort of your own home.

While working as a researcher in distributed systems, Dr. Christian Mayer found his love for teaching computer science students.

To help students reach higher levels of Python success, he founded the programming education website Finxter.com. He’s author of the popular programming book Python One-Liners (NoStarch 2020), coauthor of the Coffee Break Python series of self-published books, computer science enthusiast, freelancer, and owner of one of the top 10 largest Python blogs worldwide.

His passions are writing, reading, and coding. But his greatest passion is to serve aspiring coders through Finxter and help them to boost their skills. You can join his free email academy here.

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