Clik here to view.
Joining CSV Files in QGIS
DBF files are the other thorny issue that comes up when I’m teaching the Intro to GIS workshops with QGIS – specifically how do you create and edit them? Doing that has been pretty inconvenient in the...
View ArticleDefine Projection for a Batch of Shapefiles
I was working on a project where I had downloaded 51 shapefiles (state-based census tract files) from the Census Generalized Cartographic Boundary Files. Each file lacked a projection .prj file, so I...
View ArticleScreen Scraping Data with Python
I had a request recently for population centers (aka population centroids) for all the counties in the US. The Census provides the 2010 centroids in state level files and in one national file for...
View ArticleClik here to view.
Altering Tables in SQLite / Spatialite
In building the Spatialite geodatabase (see previous post), one of the fundamental things I learned was how to manage table creation and alteration in SQLite, which was quite different from my previous...
View ArticleCreating Reports with SQLite, Python, and prettytable
In addition to providing the NYC Geodatabase as a resource, I also wanted to use it to generate reports and build applications. None of the open source SQLite GUIs that I’m familiar with have built in...
View ArticleArticle on Working With the American Community Survey
I’ve got another article that’s just hit the presses. In this one I discuss the American Community Survey: how it differs from the Decennial Census, when you should use it versus other summary data...
View ArticleClik here to view.
Introducing – Data!
Professors invite me to their classes each semester to give students a crash course in finding data for neighborhoods in New York City, with a particular emphasis on Census data. I typically visit...
View ArticleArticle on Processing Government Data With Python
Last month I had an article published in the code{4}lib journal, about a case study using Python to process IRS data on tax-exempt organizations (non-profits). It includes a working Python script that...
View ArticleClik here to view.
Looping Through a Database to Create Reports
I’ve got a lot of ground to cover, picking up where I left off several months ago. In earlier posts I presented the concept for creating reports from sqlite databases using Python, Jinja, and LaTeX,...
View ArticleClik here to view.
Writing Functions and Building a Jinja Template
In previous posts I demonstrated how to pull data from a sqlite / spatialite data to generate reports using Python and Jinja, where Jinja2 is used as a template engine for creating LaTeX documents and...
View Article