During the last day of Christmas break I’ve spent a few hours trying to pick up Laravel again, from the beginning. I remember I blogged about Laravel back in 2016 (time flies!), and reading them again, I am surprised that what I thought back in 2016 still applies today. Today I am going to talk… Read More »
“I need to display data on a page, not perform Sub Zero’s original MK fatality.” https://hackernoon.com/how-it-feels-to-learn-javascript-in-2016-d3a717dd577f#.67qnsecr5
View story at Medium.com
Here is a quick recipe for Django templates, let’s say you are building a Django web which has many list views, and which has pagination, it’s wise to abstract the pagination template out to be reusable by all list view templates. My preference is to keep all reusable templates in a partials folder, and place the… Read More »
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. https://github.com/variable/django-rest-framework-queryset
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
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import requests # local file with open('image.jpg', 'rb') as file: resp = requests.post('http://localhost:8888/image', data=file.read()) url = resp.headers['Location'] # remote file remote_resp = requests.get(image_url, stream=True) resp = requests.post('http://localhost:8888/image', data=remote_resp.content) url = resp.headers['Location'] |
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:
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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:
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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 code:
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import threading function transform_listing(feed): cursor = feed.get_data_source().cursor() .... feed = Feed.objects.create(receiver=Database.objects.create(name='legacy')) for i in range(100): th = threading.Thread(transform_listing, [feed]) th.start() |
And you will quickly notice the threads complaining
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Too many connections |
What it’s happening is Django will create a new connection per thread… 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:
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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 client:
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public void work(){ bean.add_item(item); // this uses instance 1 in App Server .... bean.checkout(); // this uses instance 1 in App Server } |
A stateless session bean, should not store a state in the bean instance, in order words, it’s class members should… 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:
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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 object to contain the attribute GET… Read More »