If you have Mac system and created bash scripts so far, there is a fun feature on OS X that you can type say command. say will say the phrase:

say hello channel users

Or let's say you have a bash script that will take a lot of time and at the end of the script your want to hear operation done successfully from your speaker:

say operation done successfully

#osx #say #command #fun

There is a command in osX called open that will open finder for you from within of your terminal.

The great thing about this command is that you can open finder when you have traversed a long path and now you want it to have inside of finder. Go to the desired directory in your terminal using cd then use:

open .

it will open you finder. :)

#osx #open #command #fun #trick

If you get the below error for cross device link when installing npm on container:

npm WARN optional Skipping failed optional dependency /webpack/watchpack/chokidar/fsevents:
npm WARN notsup Not compatible with your operating system or architecture: fsevents@1.0.12
npm ERR! Linux 3.16.0-4-amd64
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "install"
npm ERR! node v6.3.0
npm ERR! npm  v3.10.3
npm ERR! path /app/node_modules/istanbul/node_modules/abbrev
npm ERR! code EXDEV
npm ERR! errno -18
npm ERR! syscall rename

npm ERR! EXDEV: cross-device link not permitted, rename '/app/node_modules/istanbul/node_modules/abbrev' -> '/app/node_modules/abbrev'
npm ERR! 
npm ERR! If you need help, you may report this error at:
npm ERR!     <https://github.com/npm/npm/issues>

npm ERR! Please include the following file with any support request:
npm ERR!     /app/npm-debug.log
The command '/bin/sh -c npm install' returned a non-zero code: 238

To solve this problem, put the below line of code before any npm command:

RUN cd $(npm root -g)/npm && npm install fs-extra && sed -i -e s/graceful-fs/fs-extra/ -e s/fs.rename/fs.move/ ./lib/utils/rename.js

reference: https://github.com/npm/npm/issues/13306
#npm #docker #container #cross_device

Today in django tutorial series we define 2 models in polls/models.py. One for Question and another for Choice.

from django.db import models
class Question(models.Model):
    question_text = models.CharField(max_length=200)
    pub_date = models.DateTimeField('date published')

class Choice(models.Model):
    question = models.ForeignKey(Question, on_delete=models.CASCADE)
    choice_text = models.CharField(max_length=200)
    votes = models.IntegerField(default=0)

Our model's parent class is django models.Model and each model has its own fields. You can define string field by CharField, integer by IntegerField and datetime by DateTimeField.

* The name of each field is the column name in the table.

* max_length can be given as an argument to put restrictions on field's length

* you can give a human readable name to each field by providing an optional first positional argument like pub_date which is set to date published

* you can define foreign keys by models.ForeignKey

* fields can have default value is we have set for votes by using default

Until now Django knows nothing about our polls app, we need to plug it in, in order to include it in our project. Go to saturn/settings.py and do as follow:

INSTALLED_APPS = [
    'polls.apps.PollsConfig',
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
]

Now use makemigrations command to tell Django to store new model changes in migrations folder inside of polls:

$ python manage.py makemigrations polls
Migrations for 'polls':
  polls/migrations/0001_initial.py
    - Create model Choice
    - Create model Question
    - Add field question to choice

Finally use the below command to create the tables:

$ python manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, polls, sessions
Running migrations:
  Applying polls.0001_initial... OK

migrate is smart and just applies those changes needed, if you are careful enough you can see that a file is created that is called polls.0001_initial. This file is created by our command makemigrations in the previous step.

So we've done 2 steps overall:
1- used makemigrations to create migration files.
2- applied the migration generated in step 1 by using migrate.

#python #django #migrate #models #migrate #makemigrations #django_part5

Django has an admin panel that does lots of tedious works that if you had to create yourself, it wouldn't be an easy t
ask. In this part we try to build the admin panel from ground up.

First of all an admin panel needs an admin user. So create one first:

$ python manage.py createsuperuser
Username (leave blank to use 'fc'): alireza
Email address: a***@***.com
Password:
Password (again):
Superuser created successfully.

Ok after creating the admin user, run the developement server:

$ python manage.py runserver

Now point your URL to http://127.0.0.1:8000/admin/. You should see the login page in the next post. Login and see th
e administrator page of Django.

#python #django #admin #dashboard #createsuperuser #django_part6

#login #django #admin

#django #admin #panel

Django has an admin panel that does lots of tedious works that if you had to create yourself, it wouldn't be an easy task. In this part we try to build the admin panel from ground up.

First of all an admin panel needs an admin user. So create one first:

$ python manage.py createsuperuser
Username (leave blank to use 'fc'): alireza
Email address: a***@***.com
Password:
Password (again):
Superuser created successfully.

Ok after creating the admin user, run the developement server:

$ python manage.py runserver

Now point your URL to http://127.0.0.1:8000/admin/. You should see the login page in the next post. Login and see the administrator page of Django.

#python #django #admin #dashboard #createsuperuser #django_part6


Now to see polls in admin page, you need to register you models. open polls/admin.py:

# -*- coding: utf-8 -*-
from __future__ import unicode_literals

from django.contrib import admin

from .models import Question
admin.site.register(Question)

Last 2 lines are added to register the Question model as picture below:

If you want to monitor a specific tcp port on Icinga2 you just need to add another tcp variable:

object Host "host-web" {
     import "generic-host-tpl"

     address = "YOUR_SERVER_IP_ADDRESS"
     vars.os = "Linux"

     vars.tcp["OPTIONAL_NAME"]={
         tcp_port=8181
     }

Here in above sample we are monitoring port 8181 of host-web which has the IP address of YOUR_SERVER_IP_ADDRESS (change it to your server ip address remote or local).

#linux #monitoring #sysadmin #icinga2 #host #tcp #port

In order to remove a specific document in couchDB, you just need to give delete function the document itself:

couch = couchdb.Server('http://SERVER_IP:PORT/')
 your_db = couch['your_db_name']

 # we assume you have fetched your_couch_db_doc document
 your_db.delete(your_couch_db_doc)

Use this method in preference over __del__ to ensure you're deleting the revision that you had previously retrieved. In the case the document has been updated since it was retrieved, this method will raise a ResourceConflict exception:

>>> db.delete(doc) # doctest: +IGNORE_EXCEPTION_DETAIL
         Traceback (most recent call last):
           ...
         ResourceConflict: (u'conflict', u'Document update conflict.')

#couchdb #couch #delete #remove #document #python

If you want to find an element inside of a list in MongoDB document you can use the simple find command. Let's say you have the below documents:

[{
     "food": "Ghorme",
     "creation_date": "2017-10-12 12:00:00"
     "rates": ["bad", "so_so", "not_bad", "mmmm"]
 },{
     "food": "Kebab",
     "creation_date": "2017-10-07 22:10:00"
     "rates": ["great", "not_bad", "great", "great"]
 }]

Now if you want to find a document that has the value of bad in rates, you just use the below find query:

db.foods.find({rates: "bad" }).pretty()

#mongodb #mongo #find #list #array

If you want to undo something in vim use u key and in case you want to redo an action just press ^r.

#vim #undo #redo

Setup a proxy server by using SwitchyOmega chrome addon. Download and install it from chrome store and setup the credential as picture. Use ssh -D 5300 USERNAME@YOUR_SERVER_IP to proxy your browser traffic (server should be located in Europe or America).

#proxy #switchy_omega #ssh #tunnel #socks

Machine learning full course using python.

#tensorflow #machine_learning #python #numpy #pandas

How to use if in jinja2 template engine?

Jinja2 is a modern and designer-friendly templating language for Python, modelled after Django’s templates. It is fast, widely used and secure.

If you want to use conditional statements like if inside of template engine you should use a syntax like below:

{% if status == 'success' %}
     Some text for successful procedure
 {% else %}
     Some text for not successful procedure
 {% endif %}

#python #jinja2 #template_engine #template