This is an example that accompanies a presentation I recently gave on decorators. In this example, I show how to create decorators for managing connections to SQLite3 databases.

decorator_presentation.py

from functools import wraps
import sqlite3


CONN_STR = '/tmp/foo.db'


def sqlite_conn(conn_str):
    def dec_func(func):
        @wraps(func)
        def wrap(*args, **kwargs):
            conn = sqlite3.connect(conn_str)
            cursor = conn.cursor()
            try:
                res = func(cursor, *args, **kwargs)
                conn.commit()
                return res
            finally:
                conn.close()
        return wrap
    return dec_func


@sqlite_conn(CONN_STR)
def create_tables(cursor):
    cursor.execute('create table test (id integer, desc text)')
    
@sqlite_conn(CONN_STR)
def insert_data(cursor, table, data):
    cursor.execute(f'insert into {table} values (?, ?)', data)
    
@sqlite_conn(CONN_STR)
def read_data(cursor, table):
    cursor.execute(f'select * from {table}')
    return cursor.fetchall()

create_tables()
insert_data('test', (1, 'hai'))
insert_data('test', (2, 'there'))
print(read_data('test'))