[IDEA] Saving data

[lade043]

Is your feature request related to a problem? Please describe.
When closing program everything is lost

Describe the solution you'd like
Database or file

Encryption
This data should ideally be encrypted so it can't be accessed by third-parties
Therefor probably use PyCrypto with AES

[lade043]

deutsch = Subject("Deutsch", True, False)
deutsch.add_grade_category("schriftlich", 2)
deutsch.add_grade_category("mündlich", 1)
deutsch.add_grade(Grade(15, "KA4"))

[tstst334]

"{"name": "de", "grades": {"s": (["grade": 13, "name": "K", "date": "2019-08-02 16:56:05.638399", "grade": 12, "name": "K", "date": "2019-08-02 16:56:05.638399"], 2), "m": (["grade": 12, "name": "K", "date": "2019-08-02 16:56:05.638399"], 1)}, "main_subject": True, "oral_exam": False}"

[lade043]

The serialization and deserialization is done, now only the encryption is not working. If this is done -> Pull Request