... Interfaces are just contracts or signatures and they don't know anything about implementations. Coding against interface means, the client code always holds an Interface object which is supplied by a factory. Any instance returned by the factory would be of type In...

...er. In the same way that you can add multiple items to a shopping basket and then submit that basket to process the order, you can add Bob's account entry to the transaction wrapper and then Bill's account entry to the wrapper. When all the pieces are in place then you can POST/PUT the transacti...

...ple (LSP) is a fundamental principle of object oriented design. What is it and what are some examples of its use? 31 Answer...

...Any field with the auto_now attribute set will also inherit editable=False and therefore will not show up in the admin panel. There has been talk in the past about making the auto_now and auto_now_add arguments go away, and although they still exist, I feel you're better off just using a custom save...

...t, this is often recommended where presenting visual icons is more compact and user-friendly than an equivalent list of text blurbs. Any use of image sprites can benefit from this approach. It is quite common for hotel listings icons to display amenities. Imagine a page which listed 50 hotel and ea...

...numpy as _num from numpy import oldnumeric from numpy import * from numpy.random import rand, randn from numpy.fft import fft, ifft from numpy.lib.scimath import * The log10 function you get in scipy comes from numpy.lib.scimath. Looking at that code, it says: """ Wrapper functions to more user-f...

... here. Suppose we have some data sampled from two different groups, red and blue: Here, we can see which data point belongs to the red or blue group. This makes it easy to find the parameters that characterise each group. For example, the mean of the red group is around 3, the mean of the blue...

I've been working on a website for a few months, and a lot of times when I've been trying to edit something, I have to use !important , for example : ...

I'm starting to learn Python and I've come across generator functions, those that have a yield statement in them. I want to know what types of problems that these functions are really good at solving. ...

I've read about the difference between double precision and single precision. However, in most cases, float and double seem to be interchangeable, i.e. using one or the other does not seem to affect the results. Is this really the case? When are floats and doubles interchangeable? What are the d...