elessarelfstone

SELECT table,
    formatReadableSize(sum(bytes)) as size,
    min(min_date) as min_date,
    max(max_date) as max_date
    FROM system.parts
    WHERE active
GROUP BY table

elessarelfstone

import luigi
from luigi.contrib import ftp

class UploadFileToFTP(luigi.Task):
    file_path = luigi.Parameter()
    delete_file = luigi.BoolParameter(default=False)

    def output(self):
        return ftp.RemoteTarget('ftp.example.com', self.file_path)

elessarelfstone

# To list installed distributions
wsl -l
wsl --list

# To list installed distributions along with its running status and wsl config being 1 or 2
wsl -l --verbose
wsl -l -v

# To run a specific distro
wsl -d distro_name

elessarelfstone

# change to postgres user and open psql prompt
sudo -u postgres psql postgres

# list databases
postgres=# \l

# list roles
postgres=# \du

# create role

elessarelfstone

import luigi
import time

class TimeTaskMixin(object):
    '''
    A mixin that when added to a luigi task, will print out
    the tasks execution time to standard out, when the task is
    finished
    '''
    @luigi.Task.event_handler(luigi.Event.PROCESSING_TIME)

elessarelfstone

def sync_events():
    ts = get_last_event_ts()
    if not ts:
        ts = datetime.now()

    while True:
        ts = add_new_events_to_notify(ts)
        if not ts:
            ts = get_last_event_ts()
        sleep(DB_PROCESS_TIMEOUT)

elessarelfstone

class FailedEvents(Base):
    __tablename__ = 'failed_events'
    event_id = Column(Integer, primary_key=True)
    delivered = Column(Boolean)

def get_last_event_ts() -> datetime:
    session = Session()
    max_ts = session.query(func.max(TasksEvents.ts)).\
        select_from(TasksEvents, FailedEvents).\
        filter(TasksEvents.id == FailedEvents.event_id).\

elessarelfstone

def make_conn():
    return sqlite3.connect(LUIGI_HISTORY_DBPATH)

def load_new_luigi_events(time: str) -> List[Dict]:
    """ Load luigi events which happened after some time point"""
    cursor = make_conn().cursor()
    cursor.execute(SQL, [time])
    cols = [col[0] for col in cursor.description]
    return [dict(zip(cols, row)) for row in cursor.fetchall()]

elessarelfstone

Django 2.x Cheat Sheet

Creating a virtual environment

We need to create a virtual env for our app to run in: More Here Run this command in whatever folder you want to create your venv folder

python -m venv ./venv

elessarelfstone

Django Deployment to Ubuntu 18.04

In this guide I will go through all the steps to create a VPS, secure it and deploy a Django application. This is a summarized document from this digital ocean doc

Any commands with "$" at the beginning run on your local machine and any "#" run when logged into the server

Create A Digital Ocean Droplet

Use this link and get $10 free. Just select the $5 plan unless this a production app.