Update Sqlite w/ Python: InterfaceError: Error binding parameter 0 and None Type is not subscriptable - python-3.x

Question

I've scraped some websites and stored the html info in a sqlite database. Now, I want to extract and store the email addresses. I'm able to successfully extract and print the id and emails. But, I keep getting TypeError: "'NoneType' object is not subscriptable" and "sqlite3.InterfaceError: Error binding parameter 0 - probably unsupported type" when I try to update the database with these new email addresses.
I've verified that the data types I'm using in the update statement are the same as my database (id is class int and email is str). I've googled a bunch of different examples and mucked around with the syntax alot.
I also tried removing the Where Clause in the update statement but got the same errors.
import sqlite3
import re
conn = sqlite3.connect('spider.sqlite')
cur = conn.cursor()
x = cur.execute('SELECT id, html FROM Pages WHERE html is NOT NULL and email is NULL ORDER BY RANDOM()').fetchone()
#print(x)#for testing purposes
for row in x:
row = cur.fetchone()
id = row[0]
html = row[1]
email = re.findall(b'[a-z0-9\.\-+_]+#[a-z0-9\.\-+_]+\.[a-z]+', html)
#print(email)#testing purposes
if not email:
email = 'no email found'
print(id, email)
cur.execute('''UPDATE pages SET email = ? WHERE id = ? ''', (email, id))
conn.commit
I want the update statement to update the database with the extracted email addresses for the appropriate row.

Answer 1

There are a few things going on here.
First off, you don't want to do this:
for row in x:
row = cur.fetchone()
If you want to iterate over the results returned by the query, you should consider something like this:
for row in cur.fetchall():
id = row[0]
html = row[1]
# ...
To understand the rest of the errors you are seeing, let's take a look at them step by step.
TypeError: "'NoneType' object is not subscriptable":
This is likely generated here:
row = cur.fetchone()
id = row[0]
Cursor.fetchone returns None if the executed query doesn't match any rows or if there are no rows left in the result set. The next line, then, is trying to do None[0] which would raise the error in question.
sqlite3.InterfaceError: Error binding parameter 0 - probably unsupported type:
re.findall returns a list of non-overlapping matches, not an individual match. There's no support for binding a Python list to a sqlite3 text column type. To fix this, you'll need to get the first element from the matched list (if it exists) and then pass that as your email parameter in the UPDATE.

Answer 2

.findall() returns a list.
You want to iterate over that list:
for email in re.findall(..., str(html)):
print(id, email)
cur.execute(...)
Not sure what's going on with that b'[a-z...' expression.
Recommend you use a raw string instead: r'[a-z...'.
It handles regex \ backwhacks nicely.