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.
Mac OS X 10.8 comes with Python 2.7 pre-installed by Apple. If you wish, you are invited to install the most recent version of Python 3 from the Python website (A current “universal binary” build of Python, which runs natively on the Mac’s new Intel and legacy PPC CPU’s, is available there. Brew install python WARNING: for a modern macOS (2019) this can install python3, and for python2 you really need to do: brew install python@2. Install python3: brew install python3 UPDATE: Python 3. If you install python3, pip will be installed automatically. Brew install python3.
Is Python 3 already installed?
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, ($), 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
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:
Install Python 3.5 Mac 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. 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.
Install Pandas Python Mac Terminal
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.
Bob Savage <bobsavage@mac.com>
Python on a Macintosh running Mac OS X is in principle very similar to Python onany other Unix platform, but there are a number of additional features such asthe IDE and the Package Manager that are worth pointing out.
4.1. Getting and Installing MacPython¶
Mac OS X 10.8 comes with Python 2.7 pre-installed by Apple. If you wish, youare invited to install the most recent version of Python 3 from the Pythonwebsite (https://www.python.org). A current “universal binary” build of Python,which runs natively on the Mac’s new Intel and legacy PPC CPU’s, is availablethere.
What you get after installing is a number of things:
A
Python3.9folder in yourApplicationsfolder. In hereyou find IDLE, the development environment that is a standard part of officialPython distributions; and PythonLauncher, which handles double-clicking Pythonscripts from the Finder.A framework
/Library/Frameworks/Python.framework, which includes thePython executable and libraries. The installer adds this location to your shellpath. To uninstall MacPython, you can simply remove these three things. Asymlink to the Python executable is placed in /usr/local/bin/.
The Apple-provided build of Python is installed in/System/Library/Frameworks/Python.framework and /usr/bin/python,respectively. You should never modify or delete these, as they areApple-controlled and are used by Apple- or third-party software. Remember thatif you choose to install a newer Python version from python.org, you will havetwo different but functional Python installations on your computer, so it willbe important that your paths and usages are consistent with what you want to do.
IDLE includes a help menu that allows you to access Python documentation. If youare completely new to Python you should start reading the tutorial introductionin that document.
If you are familiar with Python on other Unix platforms you should read thesection on running Python scripts from the Unix shell.
4.1.1. How to run a Python script¶
Your best way to get started with Python on Mac OS X is through the IDLEintegrated development environment, see section The IDE and use the Help menuwhen the IDE is running.
If you want to run Python scripts from the Terminal window command line or fromthe Finder you first need an editor to create your script. Mac OS X comes with anumber of standard Unix command line editors, vim andemacs among them. If you want a more Mac-like editor,BBEdit or TextWrangler from Bare Bones Software (seehttp://www.barebones.com/products/bbedit/index.html) are good choices, as isTextMate (see https://macromates.com/). Other editors includeGvim (http://macvim-dev.github.io/macvim/) and Aquamacs(http://aquamacs.org/).
To run your script from the Terminal window you must make sure that/usr/local/bin is in your shell search path.
To run your script from the Finder you have two options:
Drag it to PythonLauncher
Select PythonLauncher as the default application to open yourscript (or any .py script) through the finder Info window and double-click it.PythonLauncher has various preferences to control how your script islaunched. Option-dragging allows you to change these for one invocation, or useits Preferences menu to change things globally.
4.1.2. Running scripts with a GUI¶
With older versions of Python, there is one Mac OS X quirk that you need to beaware of: programs that talk to the Aqua window manager (in other words,anything that has a GUI) need to be run in a special way. Use pythonwinstead of python to start such scripts.
With Python 3.9, you can use either python or pythonw.
4.1.3. Configuration¶
Python on OS X honors all standard Unix environment variables such asPYTHONPATH, but setting these variables for programs started from theFinder is non-standard as the Finder does not read your .profile or.cshrc at startup. You need to create a file~/.MacOSX/environment.plist. See Apple’s Technical Document QA1067 fordetails.
For more information on installation Python packages in MacPython, see sectionInstalling Additional Python Packages.
4.2. The IDE¶
MacPython ships with the standard IDLE development environment. A goodintroduction to using IDLE can be found athttp://www.hashcollision.org/hkn/python/idle_intro/index.html.
4.3. Installing Additional Python Packages¶
There are several methods to install additional Python packages:
Packages can be installed via the standard Python distutils mode (
pythonsetup.pyinstall).Many packages can also be installed via the setuptools extensionor pip wrapper, see https://pip.pypa.io/.
4.4. GUI Programming on the Mac¶
There are several options for building GUI applications on the Mac with Python.
PyObjC is a Python binding to Apple’s Objective-C/Cocoa framework, which isthe foundation of most modern Mac development. Information on PyObjC isavailable from https://pypi.org/project/pyobjc/.
The standard Python GUI toolkit is tkinter, based on the cross-platformTk toolkit (https://www.tcl.tk). An Aqua-native version of Tk is bundled with OSX by Apple, and the latest version can be downloaded and installed fromhttps://www.activestate.com; it can also be built from source.
wxPython is another popular cross-platform GUI toolkit that runs natively onMac OS X. Packages and documentation are available from https://www.wxpython.org.
PyQt is another popular cross-platform GUI toolkit that runs natively on MacOS X. More information can be found athttps://riverbankcomputing.com/software/pyqt/intro.
4.5. Distributing Python Applications on the Mac¶
The standard tool for deploying standalone Python applications on the Mac ispy2app. More information on installing and using py2app can be foundat http://undefined.org/python/#py2app.
4.6. Other Resources¶
The MacPython mailing list is an excellent support resource for Python users anddevelopers on the Mac:
Another useful resource is the MacPython wiki: