I've looked at a few related questions on StackOverflow and at some documentation/guides regarding wrappers, all of which tells me "no," but this doesn't seem right. That said, I'm very new to programming, so ♂️
Problem: Opening and closing a database (using python/sqlite3) requires a tedious amount of repeated code (as I understand it):
connection = None
connection = sqlite3.connect(path)
conn.execute("bla bla bla")
conn.commit()
conn.close()
So, I tried to write a reusable wrapper for my functions that access the database. But it's not ideal and so far, mostly complicates the code (problems discussed afterwards):
import functools
import sqlite3
from sqlite3 import Error
conn = None # a global that I hope to get rid of soon.
def connect_db(function):
"""
wrapper that should open db, performs function, then closes db
"""
global conn
try:
conn = sqlite3.connect("journ.db")
print("connected")
except:
print("problem")
@functools.wraps(function)
def wrapper(*args, **kwargs):
return function(*args, **kwargs)
# conn.close() # unreachable code!!
return wrapper
@connect_db
def find_entry_info(user_id):
"""
Queries database regarding users' entries and returns a dictionary (k=entry_url, v=[date, time]).
"""
entry_info = {}
# entry_tags = {}
db_handler = conn.execute("SELECT entry_url, date, time FROM entries WHERE user_id=? ORDER BY date DESC, time DESC",
user_id
)
for row in db_handler:
entry_info[row[0]]=[row[1], row[2]]
return entry_info
entry_info = find_entry_info(user_id)
The problems that I know of right now:
connis a global variable, the classic "bad idea". I'm confident I can figure this one out eventually, but I'm focused more on the following:- there's no way, based on the documentation, to close the db within the wrapper after returning the needed values from the wrapped function. I could close it within the wrapped function, of course, but that defeats the point of the wrapper, and isn't any better than calling a regular function to open the database.
So, is there a clever/simple way to write a wrapper that opens/closes the database? A popular library that I'm missing? Should I try looking at python classes . . . or just accept the clutter surrounding my queries? Thanks to all in advance for your time and kindness.
