Importing Passwords from other password managers (not browsers)

I have searched for and not found any topics related to importing of passwords from other password managers, except for one re: Roboform. Not sure if that is a password manager. For example, I would like to be able to import passwords from Norton Identify Safe.

Is there a way that I can do that? (I am able to export from Norton Identify Safe into .csv or secure or unsecured .DAT file).

I too would like to transfer my passwords, from Dashlane to Avast Passwords, but although I can export them in a csv file from Dashlane I cannot import any passwords into Avast. Am I missing something? Surely this isn’t too difficult a feature to add?