Profiling Django App

   |  1623 words  |  Kracekumar

TL:DR Pyinstrument is a call stack sampling profiler with low overhead to find out time spent in your Django application. QueryCount is a simplistic ORM query count middleware that counts the number of ORM queries, finds duplicate queries, and prints them in the terminal. Django Silk is an extensive Django profiler that records the entire execution, SQL queries, source of origin, and persists the recordings. The complete Django profiler. 🔬 What’s Profiling? [Read More]
Python  Django  Profiling  Perf 

HTTPie and Print HTTP Request

   |  1521 words  |  Kracekumar

HTTPie is a command-line utility for making HTTP requests with more straightforward syntax(controversial, I agree). The interesting feature is --offline flag which prints HTTP raw request text. The client sends the HTTP request to the server, and the server responds to the request. It’s an alternate to curl. HTTP Syntax HTTP Flow and syntrax from Wikipedia. A client sends request messages to the server, which consist of a request line, consisting of the case-sensitive request method, a space, the request target, another space, the protocol version, a carriage return, and a line feed (e. [Read More]
Python  HTTP  CLI  HTTPie 

Type Check Your Django Application

   |  2791 words  |  Kracekumar

Recently, I gave a talk, Type Check your Django app at two conferences - Euro Python 2021 and PyCon India 2021. The talk was about adding Python gradual typing to Django using third-party package Django-stubs focussed heavily around Django Models. The blog post is the write-up of the talk. Here is the unofficial link recorded video of the PyCon India talk. Here is the link to PyCon India Slides. The slides to Euro Python Talk (both slides are similar). [Read More]
Python  Django  type-hints  gradual-typing  pycon-india  talk 

Python Typing Koans

   |  476 words  |  Kracekumar

Python 3 introduced type annotation syntax. PEP 484 introduced a provisional module to provide these standard definitions and tools, along with some conventions for situations where annotations are not available. Python is a dynamic language and follows gradual typing. When a static type checker runs a python code, the type checker considers code without type hints as Any. def print_name(name): print(name) planet: str = "earth" In the above example, the name argument type hint will be Any since the type hint is missing while the type hint for the planet variable is a string. [Read More]
python  Django  gradual-typing  type-hints 

Model Field - Django ORM Working - Part 2

   |  1665 words  |  Kracekumar

The last post covered the structure of Django Model. This post covers how the model field works, what are the some important methods and functionality and properties of the field. Object-Relational Mapper is a technique of declaring, querying the database tables using Object relationship in the programming language. Here is a sample model declaration in Django. class Question(models.Model): question_text = models.CharField(max_length=200) pub_date = models.DateTimeField('date published') Each class inherits from models.Model becomes a table inside the SQL database unless explicitly marked as abstract. [Read More]
python  Django  series 

Structure - Django ORM Working - Part 1

   |  584 words  |  Kracekumar

Django ORM hides a lot of complexity while developing the web application. The data model declaration and querying pattern are simplified, whereas it’s structured differently behind the scenes. The series of blog posts will explain Django ORM working(not just converting Python code to SQL), model declaration, querying (manager, queryset), supporting multiple drivers, writing custom queries, migrations etc… Consider a model definition from the Django tutorial. from django.db import models class Question(models. [Read More]
python  Django  series 

jut - render jupyter notebook in the terminal

   |  415 words  |  Kracekumar

The Jupyter Notebook is an open-source web application that allows you to create and share documents that contain live code, equations, visualizations and narrative text. Uses include: data cleaning and transformation, numerical simulation, statistical modeling, data visualization, machine learning, and much more. The definition copied from the official website. It’s becoming common to use Jupyter notebook to write books, do data analysis, reproducible experiments, etc… The file produced out of notebook follows JSON Schema. [Read More]
python  CLI  rich  jupyter  pet-project 

Five reasons to use Py.test

   |  2966 words  |  Kracekumar

Pytest library provides a better way to write tests, run the tests, and report the test results. This post is a comparison between the Python unit test standard library and pytest features and leaves out other libraries like nose2. TL;DR Single assert statement(assert a == b) over 40 different assert methods(self.assertEqual, self.assertIsInstance, self.assertDictEqual) Better and detailed error messages on failure. Useful command line options for reporting, discovering, and reporting tests like --last-failed, --collect-only. [Read More]
python  pytest 

Build Plugins with Pluggy

   |  1570 words  |  Kracekumar

Introduction The blog post is a write up of my two talks from PyGotham and PyCon India titled, Build Plugins with Pluggy. The write-up covers a trivial use-case, discusses why a plugin-based architecture is a good fit, what is plugin-based architecture, how to develop plugin-based architecture using pluggy, and how pluggy works. Link to PyCon India 2020 Talk Trivial Use Case For the scope of the blog post, consider a command-line application queries gutenberg service, processes the data, and displays the relevant information. [Read More]
python  pluggy  plugin architecture 

Render local images in datasette using datasette-render-local-images

   |  522 words  |  Kracekumar

Datasette python library lets publishing a dataset as a SQLite database and inspects them using a web browser. The database can store text, numbers, arrays, images, binary data, and all possible formats. datasette-render-images lets you save the image in the database and render the image using data-uris. Sometimes, while publishing the dataset, you may want to store the images in a separate directory for various reasons and include the relative path to the database’s images in the table. [Read More]
python  datasette