Introduction:
Python is a popular programming language and its development is maintained by the Python Software Foundation. As it is continuously improving, it is not uncommon to have multiple versions of Python installed on your system. This is particularly useful when working with different projects that have different requirements for Python version compatibility.
In this article, we will be discussing how to change the Python version on Linux operating systems, with code examples.
Prerequisites:
Before getting started, make sure you have access to the terminal or command line on your Linux system. You should also have administrative privileges to run commands as a superuser.
Verifying the Python Version:
To check which version of Python is currently set as the default, run the following command in your terminal:
python3 --version
You should see an output similar to the following:
Python 3.8.2
If you have multiple versions of Python installed, you can check them all by running the following command:
ls /usr/bin/python*
You should see a list of all the Python versions installed on your system, with their full path.
Changing the Python Version:
To change the default Python version, we will be using the update-alternatives command. The update-alternatives command allows you to set a default version for a particular application, in this case Python.
To change the default Python version, run the following command in your terminal:
sudo update-alternatives --config python3
This will show a list of all the Python versions installed on your system, along with the currently selected version. You can choose the desired version by entering its corresponding number and hitting enter.
Example:
Let's say you have Python 3.6 and Python 3.8 installed on your system and you want to change the default to Python 3.8. When you run the update-alternatives command, you will see the following output:
There are 2 choices for the alternative python3 (providing /usr/bin/python3).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/python3.6 36 auto mode
1 /usr/bin/python3.6 36 manual mode
2 /usr/bin/python3.8 38 manual mode
Press <enter> to keep the current choice[*], or type selection number: 2
In this case, to change the default to Python 3.8, you would enter 2 and hit enter.
Verifying the Changed Python Version:
To verify the change, run the following command again:
python3 --version
You should see an output similar to the following:
Python 3.8.2
This confirms that the default Python version has been changed to Python 3.8.
Conclusion:
In this article, we have discussed how to change the default Python version on Linux operating systems, with code examples. We have also covered how to verify the change. This information is useful for developers working with different projects that have different requirements for Python version compatibility.
Installing Multiple Versions of Python:
In some cases, you may need to have multiple versions of Python installed on your system. This is useful when working on different projects that have different requirements for Python version compatibility.
To install multiple versions of Python on your Linux system, you can use a package manager such as apt-get or yum.
Here's an example using apt-get:
sudo apt-get install python3.6
This will install Python 3.6 on your system, alongside the other Python versions you may have installed.
You can repeat this process for other desired versions of Python. Once all the desired versions of Python have been installed, you can switch between them as described in the previous section.
Note that you can also install multiple versions of Python using a package manager such as Anaconda, which is a distribution of Python and other open-source tools specifically designed for scientific computing and data analysis. Anaconda allows you to create separate environments for different projects, each with its own version of Python and other dependencies.
Using Virtual Environments:
Another approach to managing multiple versions of Python is to use virtual environments. A virtual environment is a self-contained environment that contains its own version of Python and any other dependencies required for a specific project. This allows you to keep your projects isolated from each other, so you can use different versions of Python for different projects without having to switch the default version.
To create a virtual environment, you can use the virtualenv or venv packages. Here's an example using virtualenv:
sudo apt-get install virtualenv
virtualenv myenv
This will create a virtual environment called myenv in your current directory. To activate the virtual environment, run the following command:
source myenv/bin/activate
You should now see the name of the virtual environment in your prompt, indicating that you are working within the virtual environment. To install a specific version of Python, use the following command:
virtualenv -p /usr/bin/python3.8 myenv
This will create a virtual environment with Python 3.8. To install other dependencies, use the pip command.
To exit the virtual environment, run the following command:
deactivate
Using virtual environments is a flexible and convenient way to manage multiple versions of Python and keep your projects isolated from each other.
Conclusion:
In this article, we have discussed how to change the default Python version on Linux operating systems, and also covered related topics such as installing multiple versions of Python and using virtual environments. This information is useful for developers working with different projects that have different requirements for Python version compatibility. Whether you need to switch between different versions or maintain separate environments for different projects, these tools and techniques will help you work effectively with Python on Linux.
Popular questions
- How do I switch between different versions of Python on Linux?
Answer: To switch between different versions of Python on Linux, you can use the "alias" command to create a new alias for the desired version of Python. For example, to create an alias for Python 3.8, run the following command in the terminal:
alias python='/usr/bin/python3.8'
This will create an alias for Python 3.8, which you can then use in place of the default version of Python. To make this alias permanent, you can add it to your shell profile file (e.g., .bashrc or .bash_profile).
- How can I check the version of Python that is currently the default on my Linux system?
Answer: To check the version of Python that is currently the default on your Linux system, open a terminal and run the following command:
python --version
This will display the version of Python that is currently the default on your system.
- How can I install multiple versions of Python on my Linux system?
Answer: To install multiple versions of Python on your Linux system, you can use a package manager such as apt-get or yum. For example, to install Python 3.6 using apt-get, run the following command in the terminal:
sudo apt-get install python3.6
This will install Python 3.6 on your system, alongside any other Python versions you may have installed.
- How can I use virtual environments to manage different versions of Python on Linux?
Answer: To use virtual environments to manage different versions of Python on Linux, you can use the virtualenv or venv packages. For example, to create a virtual environment using virtualenv, run the following commands in the terminal:
sudo apt-get install virtualenv
virtualenv myenv
This will create a virtual environment called "myenv" in your current directory. To activate the virtual environment, run the following command:
source myenv/bin/activate
To install a specific version of Python in the virtual environment, use the following command:
virtualenv -p /usr/bin/python3.8 myenv
This will create a virtual environment with Python 3.8. To exit the virtual environment, run the following command:
deactivate
- Why is it important to be able to switch between different versions of Python on Linux?
Answer: Being able to switch between different versions of Python on Linux is important because different projects may have different requirements for Python version compatibility. By switching between different versions of Python, you can ensure that each project uses the version of Python that is most appropriate for its needs, without affecting the other projects on your system. Additionally, using virtual environments allows you to keep your projects isolated from each other, so you can use different versions of Python for different projects without having to switch the default version.
Tag
Python Version Management
