If you are a good python dev, surely you follow PEP8 coding style guidelines, and surely you have installed the flake8 plugin to constantly reminding yourself to format your code properly, and surely you have valid cases that you import stuff but not used, eg. __init__.py and surely your IDE will annoy the fuck out of… Read More »
I was writing a service which import various feeds and then post to another RESTful API, simple enough as below: from django.db import connections class Receiver(PolymorphicModel): … class Database(Receiver): name = models.CharField(max_length=255) def get_data_source(self): return connections[name] Then the feed model: class Feed(models.Model): receiver = models.ForeignKey(‘Receiver’) def get_data_source(self): return self.receiver.get_real_instance().get_data_source() Then run this feed in trivial… Read More »
I have been studying Java EE and I posted a question on Stackoverflow to verify my understanding of “SessionBean”, here is the summary: Stateless bean in client: public void work(){ bean.work1(); // this uses instance 1 in App Server … bean.work2(); // this can be instance 2 in App Server } Stateful bean in… Read More »
Let’s say you have a function to process a GET parameter from a HTTP request, the bad example to do this is: def process(request): value = request.GET.get(‘name’) work(value) process(request) The above example has 2 problems: 1. This will become a nightmare to write unit tests on this function, now you need to mock the request… Read More »
PHP and Python both are dynamic typed language, so there is no point the discuss anything related in this aspect. Exception is first class citizen try: a = 1 / 0 except: print ‘Caught’ Prints ‘Caught’ Let’s look at PHP: try{ $a = 1 / 0; }catch (Exception $e){ print “Caught”; } I cannot believe… Read More »
A colleague of mine mentioned this site http://ccbv.co.uk/ which provides references and information about django class based views. Classy Class-Based Views. ccbv.co.uk The best way to understand Django’s class-based views is to see it in Classy CBV, so pick your version and jump in at the deep end.
A bit of background here about ForeignKey (many to one): If you have Order and OrderItem models, your order FK is in OrderItem model, from OrderItem model point of view, it’s Many OrderItem to One Order, in other words ManyToOne. What this implies is you need to have Order records before OrderItem records. Now, why… Read More »
Just a code snippet to demo Python script using OpenCV import cv2, time cap = cv2.VideoCapture(0) time.sleep(1) cascade = cv2.CascadeClassifier(“haarcascade_frontalface_alt.xml”) def detect(image): #faces = cascade.detectMultiScale(img, 1.1, 2, cv2.cv.CV_HAAR_SCALE_IMAGE, (20,20), (200,200)) faces = cascade.detectMultiScale(image) for _face in faces: cv2.rectangle(image, (_face[0], _face[1]), (_face[0]+_face[2], _face[1]+_face[3]), (255,255,255)) def repeat(): ret, image = cap.read() detect(image) cv2.imshow(“w1”, image) cv2.waitKey(1) while True:… Read More »
“use strict”; require.config({ baseUrl: ‘static’, paths: { jquery: ‘bower_components/jquery/dist/jquery’, foundation: ‘bower_components/foundation/js/foundation’, }, shim: { ‘foundation’: { deps: [‘jquery’] }, } }); require([‘foundation’], function(f){ $(function(){ alert(1); }); });
Django Rest Framework is a very solid api framework, but it doesn’t provide out-of-box versioning mechanism, here is my attempt to implement version specific APIs. The goal is to achieve something like http://localhost:8000/api/(resource)/ http://localhost:8000/api/v1/(resource)/ plus allowing clients to specify the version in request header (X-Version), here is how we did it. Structure in side the… Read More »