The difference between __new__ and __init__ is mainly focus on self distinction and new-style and old-style python class definition. This article will show their difference with examples.

1. Question. According to the official document tutorial of Django project, i meet below problems in the chapter “Advanced tutorial: How to write reusable apps”. Install django-polls to MySite as directed. pip –user install /Users/john/django-polls/dist/django-polls-0.1.tar.gz Run Django server after install successfully. python manage.py runserver Browse url http://127.0.0.1:8000/polls/ in a web browser and returns an error.

1. Question. As the article title said, every Django version upgrade on exist project need a lot of re-install and re-compile. That make too much trouble. Is there any easy way to do it? 2. Answer 1. First use pip freeze to export current python library to file a. Then install the exported library in new

1. Question. Now there is a project, the old version is developed in Django 1.5, the new version is developed in Django version 1.7, the new and old versions need to be developed in parallel for some time in the near future. The question is how to install 1.5 and 1.7 versions of Django simultaneously

Python built-in functions are functions provided by python for you to use directly, such as print and input, etc. As of python version 3.6.2, a total of 68 built-in functions are provided. Today, let’s take a look at python’s built-in functions as shown in the figure below.

For a Python list or tuple object, we can go through it via a for loop, which we call iteration. In Python, iteration is done by for… in, whereas in many languages, such as C, iteration lists are done by subscripts, such as below Java code.

In one word, if a function can accept another function as input parameter, such a function is called a higher order function. Python provide several higher order functions to simplify your coding, this article will introduce them with examples.

1. Slice List. Taking a partial element from a list or tuple is a very common operation. For example, how to take the first three elements from below list? >>> L = [‘Richard’, ‘Tom’, ‘Jerry’, ‘Jackie’, ‘Kevin’] You can take elements from above list like below. >>> [L[0], L[1], L[2]] [‘Richard’, ‘Tom’, ‘Jerry’] But when you

Yagmail is a python library which can make sending email simple and easy. This article will show you examples about how to use yagmail to send emails to multiple receivers with multiple attachments, it also shows the difference between yagmail and general python sending email method.