con = sqlite3.connect('db.sqlite3')
cur = con.cursor()
sql = 'SELECT id FROM ?WHERE source_id = ?'
cur.execute(sql, ('article_table', 41945,))
one = cur.fetchone()
con.close()

report errors

sqlite3.OperationalError: near "?": syntax error

reason

sqlite3 placeholder (?) Cannot be used for column or table names.
Placeholders are used to insert or retrieve values of data from the database in order to prevent SQL injection.

Solution:

con = sqlite3.connect('db.sqlite3')
cur = con.cursor()
sql = 'SELECT id FROM article_table WHERE source_id = ?'
cur.execute(sql, (41945,))
one = cur.fetchone()
con.close()