Pandas dataframe, checking if row has exceptions and creating multiple string variables depending if row shows up multiple times

Question

I'm stuck on figuring this out. I have the following df I created from output. I'm looping through to get the table_name, schema, column_name and comment. I want to make sure there is a comment present, and if there is create a string query that appends to the list query_list.

output =  [['table_name', 'schema_name', 'column_name', 'data_type', 'null?', 'default', 'kind', 'expression', 'comment', 'database_name', 'autoincrement'], ['ACCOUNT', 'SFO', '_LOAD_DATETIME', '{"type":"TIMESTAMP_LTZ","precision":0,"scale":9,"nullable":true}', 'TRUE', '', 'COLUMN', '', 'DATE of Account', 'VE'], ['ACCOUNT', 'SFO', '_LOAD_FILENAME', '{"type":"TEXT","length":16777216,"byteLength":16777216,"nullable":true,"fixed":false}', 'TRUE', '', 'COLUMN', '', 'file name', 'VE'], ['ACCOUNT', 'SFO', '_LOAD_FILE_TIMESTAMP', '{"type":"TIMESTAMP_NTZ","precision":0,"scale":9,"nullable":true}', 'TRUE', '', 'COLUMN', '', '', 'VE'], ['CUSTOMER', 'SFO', 'SUBSCRIPTIONSLIST', '{"type":"TEXT","length":16777216,"byteLength":16777216,"nullable":true,"fixed":false}', 'TRUE', '', 'COLUMN', '', '', 'VE'], ['CUSTOMER', 'SFO', 'CONTACTROLESLIST', '{"type":"TEXT","length":16777216,"byteLength":16777216,"nullable":true,"fixed":false}', 'TRUE', '', 'COLUMN', '', 'list of contract', 'VE'], ['DATA', 'SFO', 'OPPORTUNITY_NAME', '{"type":"TEXT","length":16777216,"byteLength":16777216,"nullable":true,"fixed":false}', 'TRUE', '', 'COLUMN', '', '', 'VE']]

output = filter(bool, output)
df = pd.DataFrame(output)


df.columns = df.iloc[0]
df = df[1:]

query_list = []
grouped_comments = ''

for index, row in df.iterrows():
    if row['comment'] is not None and row['comment'] != '':
        
        if len(row['table_name']) > 1:
            # the below doesn't work, it groups all table comments together

            sql = f"(COLUMN {row['column_name']} COMMENT '{row['comment']}')"
            grouped_comments = grouped_comments + sql

        elif len(row['table_name']) == 1:
            sql = f"ALTER TABLE {row['schema_name']}.{row['table_name']} ALTER COLUMN {row['column_name']} COMMENT '{row['comment']}';"

        query_list.append(sql)

Now the part I'm stuck on getting, is if there is a comment present and if the table_name shows up more then once then it should create a string that looks like the below, so it should be fetching all the column_name and comment and grouping into one string for that table_name:

"ALTER TABLE VE.ACCOUNT ALTER (COLUMN _LOAD_DATETIME COMMENT 'DATE of Account', COLUMN _LOAD_FILENAME COMMENT 'file name');"

and the elif works because if table_name only shows up once then it populates the correct string:

"ALTER TABLE VE.CUSTOMER ALTER COLUMN CONTACTROLESLIST COMMENT 'list of contract';"

so finally if I have the 2 above strings then my query_list should look like:

query_list = ["ALTER TABLE VE.ACCOUNT ALTER (COLUMN _LOAD_DATETIME COMMENT 'DATE of Account', COLUMN _LOAD_FILENAME COMMENT 'file name');",
 "ALTER TABLE VE.CUSTOMER ALTER COLUMN CONTACTROLESLIST COMMENT 'list of contract';"]