I am currently helping with some NLP code and in the code we have to access a database to get the papers. I have fun the code successfully before but every time I try to run the code again I get the error sqlite3.DatabaseError: file is not a database. I am not sure what is happening here because the database is still in the same exact position and the path doesn't change. 
I've tried looking up this problem but haven't found similar issues. 
I am hoping that someone can explain what is happening here because I don't even know how to start with this issue because it runs once but not again.
I got the same issue. I have a program that print some information from my database but after running it again and again, I got an error that my database was unable to load.  For me I think it may be because I have tried to be connected to my database that this problem occurs.  And what I suggest you is to reboot your computer or to research the way of being connected several times to the database
Getting error 'file is not a database' after already accessing the database