Category Archives: Python

Use “get” methods to help writing more testable code

Imagine you have the following code def do_something(): users = User.objects.filter(dob__gte='1980-01-01') for user in users: # do something to user If you were writing unit test against do_something(), you would need to do some complex mocking on User.objects.filter() to return some mock up data. But this can be easily prevented by refactoring into a separate… Read More »

Minimal Django script setup

import os, sys, pathlib # if script is in on 1 level deep # sys.path.append(str(pathlib.Path(__file__).parents[1].absolute())) sys.path.append(str(pathlib.Path(__file__).absolute())) os.environ.setdefault("DJANGO_SETTINGS_MODULE", "main.settings") import django django.setup() # import your django models # do your django work

Notes about python logging

Consider the following code import logging'trying to log something') Executing above: It won’t log anything to console, because it default to level warning It won’t log anything to console, because no stream has been set import logging logging.basicConfig(level=logging.INFO)'trying to log something') logging.basicConfig(level=logging.DEBUG) logging.debug('trying to log something debug') Executing above: Running basicConfig(…) default adds… Read More »

Django Rest Framework QuerySet

I have just created this python library so that you can query the remote api just like the Django queryset. It is particularly usefully when used in Django ListView with pagination. 

Posting image to thumbor using requests package

Seems like there are not many code sample there, and the requests documentation was giving the wrong hint to use files={‘file’: open(‘image.jpg’)} which you will end up getting 415 response code. I think I will just share my working sample code here to save someone’s time import requests # local file with open(‘image.jpg’, ‘rb’) as… Read More »

PHP developers should try Python.

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 »

Python OpenCV Facial Detection On OSX

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,, (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 = detect(image) cv2.imshow(“w1”, image) cv2.waitKey(1) while True:… Read More »

Django CMS Haystack 2.0 Search Index

Currently django-cms-search doesn’t support haystack 2.0 yet, so here is my modified version to work on haystack 2.0 based on import datetime from haystack import indexes from cms.models.managers import PageManager from cms.models.pagemodel import Page from cms.models.pluginmodel import CMSPlugin class PageIndex(indexes.SearchIndex, indexes.Indexable): text = indexes.CharField(document=True, use_template=False) pub_date = indexes.DateTimeField(model_attr=’publication_date’, null=True) login_required = indexes.BooleanField(model_attr=’login_required’) url = indexes.CharField(model_attr=’get_absolute_url’)… Read More »