I'm using Python (3.7.4) to make a text/password manager, where the user can store text under different tabs (using tkinter for the interface) , and use a "master login" to access all data.
The only experience I've got with saving/storing data is using CSV files, and looping through them to get values.
Can anyone recommend anyway I can store text, without it being able to be opened from Windows Explorer, and need some sort of key to be opened?
The natural alternative to using csv files is the use of a database. A solution like sqlite might be enough for your solution. Directly from the documentation:
SQLite is a C library that provides a lightweight disk-based database that doesn’t require a separate server process and allows accessing the database using a nonstandard variant of the SQL query language. Some applications can use SQLite for internal data storage. It’s also possible to prototype an application using SQLite and then port the code to a larger database such as PostgreSQL or Oracle.
Once you have learned sqlite, you can think of encrypting your database: in this post you will find many ideas for encrypting your sqlite database.
Otherwise you can switch to other more complete and complex DBMSs. The important thing is that you consider moving from the csv to using a db.