Create multiple task in airflow using loop - airflow

Question

I want to create task which will be update columns rows and send mail for every line in data table. At the moment I create task which download the data from main table. I cannot create tasks for every line in temp data table. Could you tell what I doing wrong and how I can generate and run tasks in lopp?
from datetime import datetime, timedelta
import airflow
from airflow import DAG
from airflow.contrib.operators.bigquery_operator import BigQueryOperator
from airflow.contrib.operators.bigquery_get_data import BigQueryGetDataOperator
from airflow.contrib.operators.bigquery_check_operator import BigQueryValueCheckOperator
from airflow.operators import PythonOperator
from airflow.operators.python_operator import PythonOperator
default_args = {
'owner': 'cmap',
'depends_on_past': False,
'start_date': airflow.utils.dates.days_ago(0),
'email_on_failure': False,
'email_on_retry': False,
'retries': 0,
'retry_delay': timedelta(minutes=5),
}
with DAG('dq_bigquery_test',
max_active_runs=1,
schedule_interval='#once',
catchup=False,
default_args=default_args) as dag:
query = "SELECT * from `dbce-bi-prod-e6fd.dev_dataquality.data_logging_inc` where MailRequired = false"
insert = "INSERT into dbce-bi-prod-e6fd.dev_dataquality.data_logging_inc (DataTimeStamp, Robot, Status) Values (CURRENT_TIMESTAMP(), 'TestRobot', 'Test')"
my_bq_task = BigQueryOperator(
task_id='query_exc_on_teste',
sql=query,
write_disposition='WRITE_TRUNCATE',
create_disposition='CREATE_IF_NEEDED',
bigquery_conn_id='google_cloud_dbce_bi_prod',
use_legacy_sql=False,
destination_dataset_table='dev_dataquality.testTable')
get_data = BigQueryGetDataOperator(
task_id='get_data_from_query',
project_id='dbce-bi-prod-e6fd',
dataset_id='dev_dataquality',
table_id='testTable',
max_results='100',
selected_fields='Robot,Status,MailRequired',
bigquery_conn_id='google_cloud_dbce_bi_prod'
)
def process_data_from_bq(**kwargs):
ti = kwargs['ti']
update_column = []
bq_data = ti.xcom_pull(task_ids='get_data_from_query')
print(bq_data)
# Now bq_data here would have your data in Python list
for index, i in enumerate(bq_data):
update_query = "UPDATE `dbce-bi-prod-e6fd.dev_dataquality.data_logging_inc` SET MailSent = True WHERE Robot = '{}'".format(i[0])
print(update_query)
update_column.append(BigQueryOperator(
task_id='update_column_{}'.format(index),
sql=update_query,
write_disposition='WRITE_EMPTY',
create_disposition='CREATE_IF_NEEDED',
bigquery_conn_id='google_cloud_dbce_bi_prod',
use_legacy_sql=False,
dag=dag
))
if index not in [0]:
update_column[index-1] >> update_column[index]
process_data = PythonOperator(
task_id='process_data_from_bq',
python_callable=process_data_from_bq,
provide_context=True
)
my_bq_task >> get_data >> process_data
Thank you for your help!