Python psycopg2 PostgreSQL 101

import psycopg2
url = 'postgres://username:[email protected]:1234/database'
connection = psycopg2.connect(url)
cursor.execute('SELECT * FROM table')
first_record = cursor.fetchone()        # though why not use LIMIT 1 for this?
all_records = cursor.fetchall()
print(first_record)
for a in all_records:
    print(f'{a[0]}, {a[1]}, …')
connection.close()