# Pastebin nbLllWnE
In [5]: x = set([('IMM5708', None), ('IMM1295', None)])

In [6]: y = set([('IMM5708', '2022-11-01'), ('IMM5709', '2022-09-01')])

In [7]: x.difference(y)
Out[7]: {('IMM1295', None), ('IMM5708', None)}