Unable to use otherApps Desired Capability with Python Client

I’m using Appium desktop v1.6.2 with a Python client. The app I’m testing requires a 2 other apps to be installed before I can run my test. Therefore I’m trying to use the ‘otherApps’ desired capability the prerequisite apps installed.

I have tried various formats to specify a JSON array, but I get different errors.

desired_caps['otherApps'] = ["C:\\Users\\sraheem\\Downloads\\ttm-backbone.apk", "C:\\Users\\sraheem\\Downloads\\service-debug.apk"]

Message: 'otherApps' must be of type string
desired_caps['otherApps'] = "["C:\\Users\\sraheem\\Downloads\\ttm-backbone.apk", "C:\\Users\\sraheem\\Downloads\\service-debug.apk"]"

SyntaxError: invalid syntax
desired_caps['otherApps'] = "[\"C:\\Users\\sraheem\\Downloads\\ttm-backbone.apk\", \"C:\\Users\\sraheem\\Downloads\\service-debug.apk\"]"

...Original error: The application at '["C:\Users\sraheem\Downloads\ttm-backbone.apk", "C:\Users\sraheem\Downloads\service-debug.apk"]' does not exist or is not accessible

Can anyone tell me what the right syntax to specify other apps are?