However OS X prevents me from dragging the python script to dock - seems it thinks that python script is not an executable:(. When I drag a python script into 'documents' section of dock it just don't start when clicked - an empty terminal opens, the python launcher opens for a few seconds and then nothing happens. Using: Mac OS X 10.5.7. MacOS 10.11.6 has Python 2.7.10 installed. If you want Python 3 or a later version of Python 2.7 then I would recommend using either Homebrew or Anaconda (if you want Python with a bunch of bells and whistles pre-installed) to install it. Homebrew and Anaconda currently install Python 2.7.12.

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 Python3.9 folder in your Applications folder. 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:

Hello, World!

To start, we need to get some things straight.

Programs are recipes you write to make your computer do things. These recipes are written in aprogramming language, which is a language close enough to human for you to write, and organized enough for a computer to read. Python is one of the most popular programming languages.

When you write a program, you’re just writing a text file (similar to a word document, or an email, or a short story).

When you run a program, you’re giving that text file to Python, and Python is making your computer do stuff.

Programs can do all kinds of stuff, like printing, calculating with numbers, reading a website, or sending a file.

The first program we’re going to write in this tutorial is the classic “Hello World”. Our version will print the words “Hi, Everybody!” onto the screen.

When you’re beginning to learn to program, it’s hard to do all the fancy graphics necessary to make a website or a phone app. So, to start out, most programmers learn to program using the command line. The command line is a program where you type commands and the computer outputs results. It looks like something used by old school hackers on television:

The command line is where you’ll run your first few programs. But it’s not where you’ll write them. Just as there are good places to write documents (Microsoft Word) and emails (Gmail), and good places to edit photos (Photoshop) and draw pictures (Illustrator), there are good places to write programs.

Since programs are written in text, it’s good to write them in a text editor. A text editor is just a program for writing. Microsoft Word and Gmail are text editors, but they have special features which get in the way of writing programs.

Programming has its own text editors. They range from the very light weight (some programmers just use a basic notepad) to the very heavyweight (big development environments like Eclipse and Visual Studio will automatically complete some of your code for you).

We will use a middleweight program called Sublime Text. Sublime looks like a simple notepad, but it provides what is called syntax highlighting. Programs are organized text, so showing them in colors helps highlight the important parts:

Sublime Text is available at http://www.sublimetext.com/2. Download the OS X copy, open the dmg file you downloaded, and drag the Sublime icon to your Applications folder. It is also a good idea to add this program to your dock.

The command line program in OS X is called Terminal. You can find it in your Applications folder inside another folder called Utilities.

Open Sublime to a blank file. In that file, write:

Save this file to your home directory as “helloworld.py”.

Later we will learn how to navigate files at the terminal, but for now, saving to your home directory will allow use to run the program without worrying about where it is located.

Notice how after you save the file, Sublime starts highlighting it, turning the word “print” one color, and the text another color. This is because, by naming the file with a “.py” at the end, you’ve helped Sublime to guess that this is a python file, and it has applied Python language highlighting.

Open the Terminal program. Some text is printed to say who you are and when you last logged in, but we’ll worry about that later. Right now, we’re only concerned with the prompt. The prompt is the line you’re currently typing on. You can type anything you want, but when you press enter, your computer will assume you have given it a command and try to execute that command.

We will command the computer to run our new Python program. At the prompt, type the following and press enter:

On the line below the prompt, the terminal should print:

Below this line, it should print another prompt, indicating that it is waiting for you to give another command.

And there you go! You made the computer print something out to the terminal.

In the Python language, the word “print” tells the computer to output text to the terminal. The text you want to print is wrapped in quotes. So,

tells the computer to print the text “Hi, Everybody!”.

In the next post, you will learn how to use Python to do calculations and print numbers.