Saves the icon of a running app with a given pid

save_icon_osx.py

import sys
from Cocoa import NSDictionary, NSNumber
from AppKit import NSRunningApplication, NSImageCompressionFactor, NSBitmapImageRep, NSPNGFileType


app = NSRunningApplication.runningApplicationWithProcessIdentifier_(int(sys.argv[1]))
icon = app.icon()
image_data = icon.TIFFRepresentation()
image_rep = NSBitmapImageRep.imageRepWithData_(image_data)
image_props = NSDictionary.dictionaryWithObject_forKey_(NSNumber.numberWithFloat_(1.0), NSImageCompressionFactor)
image_data = image_rep.representationUsingType_properties_(NSPNGFileType, image_props)
file_name = "{}.png".format(app.localizedName())
image_data.writeToFile_atomically_(file_name, False)