crsr.execute('SELECT firstname FROM pytest')
fname = crsr.fetchone()[0]
print(fname)
try:
    crsr.fetchall()
except mysql.connector.errors.InterfaceError as ie:
    if ie.msg == 'No result set to fetch from.':
        pass
else:
    raise
crsr.execute('SELECT firstname FROM pytest')
Python MySQL connector - unread result found when using fetchone