Python

October 5, 2014

My Testing Strategy – How to use Lettuce to test, switching between test and development database when Django uses SQLAlchemy.

I haven’t started doing any automation testing, and I know it is important; therefore, I start thinking about a good way to do tests, being more specific, at this stage, I want to focus on browser behavior testing. I quickly found out something called Watir WebDriver, which is in Ruby. Since everything here is written in Python, although personally I want to learn some Ruby, it will become very hard if I will have any testing related to database. Therefore, I kept looking until I found Lettuce. Lettuce has built-in integration with Django, however for some of the features to work, it assumes that you are using the default Django ORM, which is not the case here at KuKy World because we use SQLAlchemy.

Now, I am going to talk what we do to switch between our test and development database. First of all, my testing strategy is the following: I have a features folder under each of my registered app, and in each features folder, I have two sub folders: backend, which is for testing on the back end, and web, which is testing on the browser. The file structure will look this:

In order to make the testing use test database, I will have to define the test database environment in terrain.py file, the following is what I did:

from lettuce import world
import sqlalchemy, sqlalchemy.orm
from sqlalchemy.ext.declarative import declarative_base

def recrete_test_db():
    testing_db = 'mysql://root:@localhost/test'
    engine = sqlalchemy.create_engine(testing_db)
    Session = sqlalchemy.orm.sessionmaker(bind=engine)
    world.session = Session()
    Base = declarative_base()
    # import all the models
    from webapp.models import *
    # Re create the tables in test database
    Base.metadata.drop_all(engine)
    Base.metadata.create_all(engine)

world.recrete_test_db = recrete_test_db

and then in my signup.py file, you can recreate your test database anywhere based on your need, here is an example:

from lettuce import *

@before.all
def say_hello():
    print 'Hello there!'
    print 'Lettuce will recreate the test database and run tests...'
    world.recrete_test_db()

Note: when you communicate with your test database in tests, you will be using world.session rather than other sessions you might have at your global level.

Thanks for reading.

September 26, 2014

My resume template – XNemo.

A lot of people ask me about what I use to write my resume, here is a copy, it is obviously LaTeX. The confusion they have is that my resume looks like some popular latex templates combined. Indeed, I did some customization of two popular templates, and added some other stuff, eventually turned it into what my resume looks like now.

Today I am using Jinja environment to turn my static LaTeX resume into a template which will later read a JSON file to fill in the content. I call it XNemo, you can download it here, and apply to your own resume. It requires no knowledge of coding, but a bit of JSON.

Now, I will go into some of the details how I designed this, and how you can use it for your own resume.

After you download the code, you should see the following file structure, pretty simple.

At a high level, how it works is also easy to understand: you run a python script, it will read the content of data.json to templates/template.tex file, and generate the LaTeX source file resume.tex and the final resume.pdf file. What you need to do is simple, just type the following two commands.

Note: Make sure you have Flask installed, otherwise you will get errors.

Now I will explain some of the details.

First, I defined my own template block syntax in generate_pdf.py as the following:

Basically, when I set block_start_string to ‘((*’, and block_end_string to ‘*))’, that means your for loop in the LaTeX template will look like: ((* for <condition> *)) ((* endfor *)), setting variable_start_string will make your variable value retrieval looks like <(( value ))>. From line 57 to line 60, I customized some template tags that later will be used in the template.

Now let’s take a look at data.json file. My resume contains multiple different colors, and timeline, and this block of info simply defines them:

When you set “usecolor” to true, the timeline color and the theme color will be applied to your resume, false will make your resume look pure black and white. Since my resume has timeline, “start_year” will be the earliest year that will appear in your resume, and the default hidden “end_year” is just next year. “theme_color” defines all the other colors besides the timeline colors (including the quote).

For the rest in the data.json file, it defines your skills, working experience, projects, education, and interests, the most common things you will most likely be interested in having them in your resume, and how it works is very self explained.

If you want to add more content to you resume, you can look through data.json and templates/template.tex, and modify them into what fits you, which might require a bit of knowledge of LaTeX and JSON, but it is still not too hard.

If you have any questions, you can always send me a request or comment on this blog. I will respond as soon as possible.

Thanks for reading.