Cannot access an sqlite3 database file with python

Question

I'm trying to take recipe hyperlinks from a pre-existing file and add them to a table in a database. I have already created the database and given the file name to set up a connection and insert the data into the table but whenever I do so I get the error sqlite3.OperationalError: unable to open database file. Here's my code:

import bs4, os, requests, time
import sqlite3
from flask import current_app, g

def create_connection(db_file):
    db = sqlite3.connect(db_file)
    c = db.cursor()

    return db


def get_html():
    '''
    Get the BBC Food sitemap and save it to a local file.
    '''
    page = None
    db = create_connection("pantry/instance/flaskr.sqlite")
    for attempt in range(1, 4):
        print("line 40")
        page = requests.get('http://www.bbc.co.uk/food/sitemap.xml')
        try:
            page.raise_for_status()
            break
        except requests.RequestException:
            time.sleep(attempt * 10)

    if not page:
        raise Exception('Failed to get sitemap.xml')

    sitemap = bs4.BeautifulSoup(page.text, 'html.parser')
    # Write the recipe urls to a text file
    print("line 53")
    for line in sitemap.find_all('loc'):
        for string in line.stripped_strings:
            if string.startswith('https://www.bbc.co.uk/food/recipes/'):
                print("line 57")
                recipeUrl = string
                if (
                        db.execute("SELECT recipeID FROM recipe WHERE weblink = ?", (recipeUrl,)).fetchone()
                        is not None
                ):
                    error = "recipe weblink {0} is already inputted.".format(recipeUrl)
                if error is None:
                    db.execute(
                        'INSERT INTO recipe (weblink) VALUES (?)',
                        recipeUrl
                    )
                    db.commit()
    db.close()

And the error message:

Traceback (most recent call last):
File "<input>", line 1, in <module>
  File "C:\Program Files\JetBrains\PyCharm 2019.2.2\helpers\pydev\_pydev_bundle\pydev_umd.py", line 197, in runfile
    pydev_imports.execfile(filename, global_vars, local_vars)  # execute the script
  File "C:\Program Files\JetBrains\PyCharm 2019.2.2\helpers\pydev\_pydev_imps\_pydev_execfile.py", line 18, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "C:/Users/Eva Morris/PycharmProjects/pantry/flaskr/BBCscraper/scraperecipes.py", line 161, in <module>
    get_html()
  File "C:/Users/Eva Morris/PycharmProjects/pantry/flaskr/BBCscraper/scraperecipes.py", line 34, in get_html
    db = create_connection("pantry/instance/flaskr.sqlite")
  File "C:/Users/Eva Morris/PycharmProjects/pantry/flaskr/BBCscraper/scraperecipes.py", line 23, in create_connection
    db = sqlite3.connect(db_file)
sqlite3.OperationalError: unable to open database file

Answer 1

Based on the consoles error report, your .py file is located in: C:/Users/Eva Morris/PycharmProjects/pantry/flaskr/BBCscraper/scraperecipes.py".

In your code you set your databases directory using the relative path as:pantry/instance/flaskr.sqlite.

This means python is looking for the directory: C:/Users/Eva Morris/PycharmProjects/pantry/flaskr/BBCscraper/pantry/instance/ to create/link your database file in.

If that is not a preexisting directory, sqlite3.connect will not be able to create your database flaskr.sqlite.

You may need to update the code db = create_connection("pantry/instance/flaskr.sqlite") to something like db = create_connection("flaskr.sqlite") which should work without any problem since it will just create the database in your working directory.