You can try the pywin32 library. After you import the win32com part, the following script accesses the EA interface:
App = win32com.client.dynamic.Dispatch("EA.App")
EA = App.Repository
if not EA.OpenFile("PATHTOYOUR.eap"):
print ("load failed")
for package in EA.Models:
print(package.Name);
Project = EA.GetProjectInterface()
Project.Exit()
I don't know how you develop an addin for EA, but that should you get started.