How do I store desktop application data in a cross platform way for python?

Well, I hate to have been the one to answer my own question, but no one else seems to know. I'm leaving the answer for posterity.

APPNAME = "MyApp"import sysfrom os import path, environif sys.platform == 'darwin':    from AppKit import NSSearchPathForDirectoriesInDomains    # http://developer.apple.com/DOCUMENTATION/Cocoa/Reference/Foundation/Miscellaneous/Foundation_Functions/Reference/reference.html#//apple_ref/c/func/NSSearchPathForDirectoriesInDomains    # NSApplicationSupportDirectory = 14    # NSUserDomainMask = 1    # True for expanding the tilde into a fully qualified path    appdata = path.join(NSSearchPathForDirectoriesInDomains(14, 1, True)[0], APPNAME)elif sys.platform == 'win32':    appdata = path.join(environ['APPDATA'], APPNAME)else:    appdata = path.expanduser(path.join("~", "." + APPNAME))

There's a small module available that does exactly that:

https://pypi.org/project/appdirs/

You can try to use QSettings from Qt. You can obtain the path to your MyCompany/MyApp.ini file this way:

from PySide.QtCore import QSettings, QCoreApplicationQSettings.setDefaultFormat(QSettings.IniFormat)QCoreApplication.setOrganizationName("MyCompany")QCoreApplication.setApplicationName("MyApp")settings = QSettings()print(settings.fileName())

Alternatively, without changing any global state:

QSettings(    QSettings.IniFormat, QSettings.UserScope,    "MyCompany", "MyApp").fileName()

On Win7 you get something like:

C:\Users\MyUser\AppData\Roaming\MyCompany\MyApp.ini

On Linux (may vary):

/home/myuser/.config/MyCompany/MyApp.ini

I don't know the possible results for OSX (but I'd like to).

QSettings functionallity seem to be nice until you want to use registerFormat, which is not available in PySide, so there is no easy way to use YAML or JSON writers for settings.