Category: python

Assertions is one of the most advanced Exception Handling technique used in python by using the Assert statement,we can create debug message,if anything logically end up with an error.If anything fails logically AssertionError will display and end the process. here we will check assertion error python
When we are working with automatic car project their is a situation of fuel tank is empty that time we have to stop all process and stop the vehicle with an error message “no fuels”

See the syntax here

assert Expression[, Arguments]

Example:
Create a fuel.py file with below function

def fuelLevel(fuel):
   assert (fuel > 0),"Sorry no fuel in the system"
   print(fuel)

   
   
fuelLevel(4)
fuelLevel(0)

Run from command prompt

we know that Django is one of the most popular framework in python.we already discussed how to install a Djnago frame work in windows .Now we have installed Djnago framework in our system.We read Djnago provide build-in admin panel automaticaly ,so our question is what is the user name and password for admin Django,here am going to explain How to create new admin user in Django.

In Django default admin url is http://127.0.0.1:8000/admin/login/?next=/admin/,when you type http://127.0.0.1:8000/admin/login/?next=/admin/ in your browser ,you will get below User Interface

To Login above admin side we need admin user name and password ,see here how to create new admin user in Django

python manage.py createsuperuser

It will ask you new admin user info for your Djnago dashboard

When an running my Django python application am getting an error “Module Not found error no module named celery”. as the error says no module celery is not their in system.Since module named celery is not their with sytem we are getting an error “Module Not found error no module named celery in Python Django”.To solve this error “Module Not found error no module named celery in Python Django”, we have to install celery module in your system, to install celery we have to use PIP command.if pip is not installed with your first you to install pip after run below commands .

Install celery module in Django python

# pip install celery

session is one of the key variable for programmers,it allowing to connect the website pages easily,in simple if we store session variable in one page you can access from other pages the same values.Sessions are the technique used by Django for keeping track of the “state” between the site and a browser.Here we are checking declare a session Variable in Django Python
When we are creating a project in Django,Sessions were enabled automatically inside setting.py see below

INSTALLED_APPS = [
    ...
    ...
    'django.contrib.sessions',
    ....

MIDDLEWARE = [
    ...
    ...
    'django.contrib.sessions.middleware.SessionMiddleware',
    ....

Lets see how we can assign a session variable

# Set a session value my_visite to 1
request.session['myweb_visits'] = '1'

# if not Set it automatically declare as 0
myweb_visits= request.session.get('myweb_visits', 0)

request.session['myweb_visits'] = myweb_visits + 1

#To Get session variable myweb_visits value
myweb_visits= request.session['myweb_visits']

# To delete session myweb_visits
del request.session['myweb_visits']

Example Code

Open urls.py files add test URL

from django.urls import path
from . import views

urlpatterns = [
    path('', views.index, name='index'),
    path('test/', views.myweb_visits, name='myweb_visits'),
]

Add myweb_visits function in view.py bottom

def myweb_visits(request):
    num_visits = request.session.get('num_visits', 0)
    request.session['num_visits'] = 1 + num_visits
	
    x = num_visits + 1

    return HttpResponse("your visitng the websites : "+ str(x))

See declare-session-variable-django-python result in below Output Images