simplest-osx-python-app.md

Simplest app can be created via https://gist.github.com/mathiasbynens/674099 e.g.

mkdir -p MyApp.app/Contents/MacOS
printf '#!/bin/bash\nsleep 5' > MyApp.app/Contents/MacOS/MyApp
chmod +x MyApp.app/Contents/MacOS/MyApp
echo "<plist><dict></dict></plist>" > MyApp.app/Contents/Info.plist

But more "appy" app can be done via the followning steps

Create app dir structure

mkdir -p MyApp.app/Contents/MacOS
mkdir -p MyApp.app/Contents/Resources

Create app property list MyApp.app/Contents/Info.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>CFBundleExecutable</key>
	<string>MyApp</string>
	<key>CFBundleGetInfoString</key>
	<string>MyApp</string>
	<key>CFBundleIconFile</key>
	<string>MyApp.icns</string>
	<key>CFBundleName</key>
	<string>MyApp</string>
	<key>CFBundlePackageType</key>
	<string>APPL</string>
</dict>
</plist>

Create app executable MyApp.app/Contents/MacOS/MyApp

#!/bin/bash
/usr/bin/python $(cd "$(dirname "${BASH_SOURCE[0]}")/../Resources" && pwd)/main.py

Create app icon MyApp.app/Contents/Resources/MyApp.icns, e.g. https://gist.github.com/andreif/1691ee0a22458e4a6589

Create python app MyApp.app/Contents/Resources/main.py, e.g.

# coding=utf-8
# Source: http://www.tkdocs.com/tutorial/firstexample.html

import sys
py2 = sys.version_info.major == 2
if py2:
    from Tkinter import *
    import Tkinter as ttk
else:
    from tkinter import *
    import tkinter as ttk


def calculate(*args):
   try:
       value = float(feet.get())
       meters.set((0.3048 * value * 10000.0 + 0.5)/10000.0)
   except ValueError:
       pass

root = Tk()
root.title("Feet to Meters")
if py2:
    mainframe = ttk.Frame(root)
else:
    mainframe = ttk.Frame(root, padding="3 3 12 12")
mainframe.grid(column=0, row=0, sticky=(N, W, E, S))
mainframe.columnconfigure(0, weight=1)
mainframe.rowconfigure(0, weight=1)

feet = StringVar()
meters = StringVar()

feet_entry = ttk.Entry(mainframe, width=7, textvariable=feet)
feet_entry.grid(column=2, row=1, sticky=(W, E))

ttk.Label(mainframe, textvariable=meters).grid(column=2, row=2, sticky=(W, E))
ttk.Button(mainframe, text="Calculate", command=calculate).grid(column=3, row=3, sticky=W)

ttk.Label(mainframe, text="feet").grid(column=3, row=1, sticky=W)
ttk.Label(mainframe, text="is equivalent to").grid(column=1, row=2, sticky=E)
ttk.Label(mainframe, text="meters").grid(column=3, row=2, sticky=W)

for child in mainframe.winfo_children():
   child.grid_configure(padx=5, pady=5)

feet_entry.focus()
root.bind('<Return>', calculate)

root.mainloop()

Enjoy the result

To change app name in the OS X menu bar from Python to e.g. MyApp, use pyobjc, which is pre-installed in the system Python (/System/Library/Frameworks/Python/...):

from Foundation import NSBundle
bundle = NSBundle.mainBundle()
info = bundle.localizedInfoDictionary() or bundle.infoDictionary()
info['CFBundleName'] = 'MyApp'

To prevent multiple instances of the same app:

try:
    import fcntl
    lockfile = open('/tmp/myapp.lock', 'w')
    fcntl.lockf(lockfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
except IOError as e:
    exit()

To focus on the already running instance is a bit hard atm, so we focus on all Python.app instances, until there is a better solution available/known

from Foundation import NSWorkspace
from Cocoa import NSApplicationActivateAllWindows, NSApplicationActivateIgnoringOtherApps

for app in NSWorkspace.sharedWorkspace().runningApplications():
    if app.bundleIdentifier() == 'org.python.python':
        app.activateWithOptions_(NSApplicationActivateAllWindows | NSApplicationActivateIgnoringOtherApps)

One could use a pid file as a temporary solution

from Foundation import NSProcessInfo
info = NSProcessInfo.processInfo()
pid = info.processIdentifier()
with open(PID_FILE, 'w+') as f:
    f.write(str(pid))

try:
    with open(PID_FILE) as f:
        pid = int(f.read())
except:
    pid = None

for app in NSWorkspace.sharedWorkspace().runningApplications():
    if app.bundleIdentifier() == 'org.python.python':
        if not pid or pid == app.processIdentifier():
            app.activateWithOptions_(NSApplicationActivateAllWindows | NSApplicationActivateIgnoringOtherApps)

andreif/simplest-osx-python-app.md