The airport codes may refer to either IATA airport code, a three-letter code which is used in passenger reservation, ticketing and baggage-handling systems, or the ICAO airport code which is a four letter code used by ATC systems and for airports that do not have an IATA airport code (from wikipedia).
Airport codes from around the world. Downloaded from public domain source http://ourairports.com/data/ who compiled this data from multiple different sources. This data is updated nightly.
##Data
There is one csv file ,"airport-codes" which contains the list of all airport codes, the attributes are identified in datapackage description. Some of the columns contain attributes identifying airport locations, other codes (IATA, local if exist) that are relevant to identification of an airport
##Preparation
Download and clean the csv file as is from the url http://ourairports.com/data/
TODO: Add relationship to UNLOCODEs ?
##License
The source specifies that the data can be used as is without any warranty. Given size and factual nature of the data and its source from a US company would imagine this was public domain and as such have licensed the Data Package under the Public Domain Dedication and License (PDDL).