Only create SQLite connection when needed

src/db_client.py

@@ -1,12 +1,14 @@
 import sqlite3
 
+from contextlib import closing
+
 class DBClient:
     def __init__(self, path):
         self.path = path
-        self.con = sqlite3.connect(path)
-        self.con.row_factory = sqlite3.Row
 
     def select(self, table, rows=['*'], where='1'):
-        cursor = self.con.cursor()
-        cursor.execute(f'SELECT {", ".join(rows)} FROM {table} WHERE {where};')
-        return cursor.fetchall()
+        with closing(sqlite3.connect(self.path)) as conn:
+            conn.row_factory = sqlite3.Row
+            with closing(conn.cursor()) as cursor:
+                cursor.execute(f'SELECT {", ".join(rows)} FROM {table} WHERE {where};')
+                return cursor.fetchall()