Historically MacOS came preinstalled with Python 2, however starting with Mac 10.15 (released in October 2019) this is no longer the case. And since Python 2 will no longer be officially supported as of January 1, 2020, you should really use Python 3 instead.
There are multiple ways to install Python 3 on a MacOS computer. The official Python website even recommends downloading it directly, however this approach can cause confusion around PATH variables, updates, and uninstalls. A better approach, in my opinion, is to instead use the popular package manager Homebrew which automates updates and juggling multiple versions of Python on a computer.
Is Python 3 already installed?
All FREE Courses - to install Python on MacOSStep by Step for BeginnersToday we will learn:1. Check if Python is already.
Before we start, make sure Python 3 isn't already installed on your computer. Open up the command line via the Terminal application which is located at Applications -> Utilities -> Terminal.
Then type the command python --version followed by the Enter key to see the currently installed version of Python.
Note: The dollar sign, ($ Gorilla power mac os. ), indicates user input. Everything after is intended to be typed by the user followed by the Enter key. Any output, such as Python 2.7.17 in this case, does not have a dollar sign in front.In short: don't type $ before your commands!
It's possible that Python 3 may have already been installed as python3. Run the command python3 --version to check, however most likely this will throw an error.
Install XCode
- Mac OS X comes with Python 2.7 out of the box. You do not need to install or configure anything else to use Python 2. These instructions document the installation of Python 3. The version of Python that ships with OS X is great for learning, but it's not good for development.
- Python Releases for Mac OS X. Latest Python 3 Release - Python 3.4.0; Latest Python 2 Release - Stable Releases. Python 2.7.8 - July 2, 2014. Download Mac OS X 32-bit.
- There is a known issue with version 3.7 of Anaconda Python and certain versions of the Mac OSX operating system. We strongly recommend that you use python 3.6 on OSX to avoid any problems. To install python 3.6, please follow the steps below: To get started you need to download the OSX miniconda installer.
- Install Python 3 on MacOS. Historically MacOS came preinstalled with Python 2, however starting with Mac 10.15 (released in October 2019) this is no longer the case.And since Python 2 will no longer be officially supported as of January 1, 2020, you should really use Python 3 instead. There are multiple ways to install Python 3 on a MacOS computer.
The first step for Python 3 is to install Apple's Xcode program which is necessary for iOS development as well as most programming tasks. We will use XCode to install Homebrew.
In your Terminal app, run the following command to install XCode and its command-line tools:
It is a large program so this make take a while to download. Make sure to click through all the confirmation prompts XCode requires.
Install Homebrew
Next install Homebrew by copy/pasting the following command into Terminal and then type Enter:
To confirm Homebrew installed correctly, run this command:
Install Python 3
Now we can install the latest version of Python 3. Type the following command into Terminal and press Enter:
To confirm which version of Python 3 was installed, run the following command in Terminal:
Finally, to run our new version of Python 3 open an interactive shall by typing python3 within Terminal:
To exit the Python 3 interactive shell, you can type either exit() and then Return or type Control+d which means hold both the Control and D keys at the same time.
Note that it is still possible to run Python 2 by simply typing python:
Virtual Environments
By default, Python packages are installed globally on your computer in a single directory. This can cause major problems when working on multiple Python projects!
For example, imagine you have Project A that relies upon Django 1.11 whereas Project B uses Django 2.2. If you naively installed Django on your computer, only the latest install would be present and available in that single directory. Hell invasion mac os. Then consider that most Python projects rely on multiple packages that each have their own version numbers. There's simply no way to keep everything straight and not inadvertently break things with the wrong package versions.
The solution is to use a virtual environment for each project, an isolated directory, rather than installing Python packages globally.
Confusingly, there are multiple tools for virtual environments in Python:
- venv is available by default on Python 3.3+
- virtualenv must be installed separately but supports Python 2.7+ and Python 3.3+
- Pipenv is a higher-level tool that automatically manages a separate virtual environment for each project
On MacOS we can install Pipenv with Homebrew.
Then use Pipenv for any Python packages you wish to install. For example, if you want to work with Django 2.2.6, first create a dedicated directory for it on your computer such as in a django directory on your Desktop.
Then install Django within that directory.
If you look within the directory there are now two new files, Pipfile and Pipfile.lock, which Pipenv uses. To activate the virtual environment type pipenv shell.
There will now be parentheses around the name of your current directory which indicates the virtual environment is activate. To exit the virtual environment, type exit.
The lack of parentheses confirms the virtual environment is no longer active.
Next Steps
To learn more about Python, the books Python Crash Course and Automate the Boring Stuff are great resources. For free tutorials on web development with Python check out Learn Django.
Maria Campbell provides a post on installing the latest version of Python on Mac OS Catalina and overriding the old default pre-installed version. And it even uses Homebrew and not some gnarly steps.
I finally did it. I successfully installed Python version 3.7.7 via Homebrew on my Maclaptop with OS Catalinainstalled.
How To Use Python On Mac
Then install Django within that directory.
If you look within the directory there are now two new files, Pipfile and Pipfile.lock, which Pipenv uses. To activate the virtual environment type pipenv shell.
There will now be parentheses around the name of your current directory which indicates the virtual environment is activate. To exit the virtual environment, type exit.
The lack of parentheses confirms the virtual environment is no longer active.
Next Steps
To learn more about Python, the books Python Crash Course and Automate the Boring Stuff are great resources. For free tutorials on web development with Python check out Learn Django.
Maria Campbell provides a post on installing the latest version of Python on Mac OS Catalina and overriding the old default pre-installed version. And it even uses Homebrew and not some gnarly steps.
I finally did it. I successfully installed Python version 3.7.7 via Homebrew on my Maclaptop with OS Catalinainstalled.
How To Use Python On Mac
Update Python On Mac
For those of you that still might be trying to figure out how to do this, I will walk you through.
The reason why I was eager to make sure that I had the latest version installed was because I am working on publishing (open-source) teaching-related documentation on Read The Docs, and I need to have Python installed in order to be able to install the programs necessary to publish there.
The default 2.7.17 version of Python was retired this past January 2020. I had tried back then to replace it with Python 3+, but was unsuccessful at the time.
They key appears to be also adding the following at the bottom of the .zshrc file to update the path to the newly installed version of Python via Homebrew:
See all the steps in the blog post here and podcast here.
