Fix database_setup and main lint smells.

database_setup/create_database.py

@@ -1,15 +1,13 @@
-"""
-Small script to create the database if it doesn't already exist.
-"""
+"""Small script to create the database if it doesn't already exist."""
 
 import sqlite3
-from os.path import exists
+from pathlib import Path
 
-if not exists("database/dakiny.db"):
+if not Path("database/dakiny.db").exists():
     with sqlite3.connect("database/dakiny.db") as con:
         cur = con.cursor()
 
-        with open("database_setup/database.sql", encoding="utf-8") as file:
+        with Path("database_setup/database.sql", encoding="utf-8").open() as file:
             database_script = file.read()
             cur.executescript(database_script)
             con.commit()