anna-anisienia

from prefect.tasks.prefect.flow_run import FlowRunTask
from prefect import Flow
from prefect.schedules import Schedule
from prefect.schedules.clocks import CronClock

schedule_parent_flow = Schedule(clocks=[CronClock("0 2 * * *")])


with Flow("MasterFlow", schedule=schedule_parent_flow) as flow:
    staging_area = FlowRunTask(flow_name='staging_area',

anna-anisienia

from prefect.schedules import Schedule
from prefect.schedules.clocks import CronClock
import pendulum

schedule = Schedule(clocks=[CronClock("0 2 * * *",
                                      start_date=pendulum.datetime(2020, 8, 28,
                                                                   tz="Europe/Berlin")
                                      )])
schedule.next(3)  # to see next 3 schedules

anna-anisienia

import os
import contextlib
import mysql.connector


@contextlib.contextmanager
def get_mysql_conn(db):
    """
    Context manager to automatically close DB connection. 
    We retrieve credentials from Environment variables

anna-anisienia

import pandas as pd
from mysql_conn import get_mysql_conn

with get_mysql_conn(db='mytestdb') as conn:
    df = pd.read_sql('SELECT * FROM mytable', conn)

anna-anisienia

import os
import contextlib
import boto3

s3 = boto3.client('s3', aws_access_key_id='my_aws_access_key',
                  aws_secret_access_key='my_aws_secret_key',
                  region_name='eu-central-1')


@contextlib.contextmanager

anna-anisienia

with open('data.txt', 'w') as myfile:
    myfile.write('Hello from context manager!')

anna-anisienia

with open('data.txt', 'r') as myfile:
    data = myfile.read()

print(data)
# 'Hello from context manager!'

anna-anisienia

myfile = open('data.txt', 'w')
myfile.write('Hello from context manager!')
myfile.close()

anna-anisienia

myfile = open('data.txt', 'w')
try:
    myfile.write('Hello from context manager!')
finally:
    myfile.close()

anna-anisienia

-- Get the 100 most recently added data points
SELECT time, truck_id, model, 
measure_name, measure_value::double 
FROM "sampleDB"."IoT" 
ORDER BY time DESC LIMIT 100;