Concatenate every value in list to every value in column

I have a list of strings that I’d like to concatenate to every value in a column. Basically if there are 20 values in the column and 5 in the list it would now have 100 rows. The list of tenant IDs comes a thousand lines up in the code, but it’s basically every unique value in the tenantid column. Using dummy data below for propietary reasons.

tenant_ids = ["abc", "def", "ghi"]

tids = []
for t in tenant_ids:
    day_1_rules['_id'] = t+'-'+day_1_rules['_id']
    tids.append(day_1_rules)
day_1_rules = pd.concat(tids)

After running this it concatenated every value in the list so it was like abc-def-ghi-rule instead of
abc-rule
def-rule
ghi-rule

What I got

What it should be

>Solution :

from itertools import product

tenant_ids = ["abc", "def", "ghi"]
day_1_rules = pd.DataFrame({'_id': ['Rule_1', 'Rule_2', 'Rule_3']})

pd.DataFrame({'_id': [f'{tid}-{rule}' for tid,rule in product(tenant_ids, day_1_rules['_id'])]})