If you have come across a large number of freeform address as a single string, for example – “9 Downing St Westminster London SW1A, UK”, you know how hard it would be to validate, compare and deduplicate these addresses. To start with you’ll have to split this address into a more structured form with house number, street name, city, state, country and zip code separately.
Its quite easy to do this using python.
Available Python Packages to Parse Addresses
Python provides few packages to do this –
- Address – This package is an address parsing library, it takes the guesswork out of using addresses in your applications.
- USAAddress – USAAddress is a python library for parsing unstructured address strings into address components, using advanced NLP methods. You can try their web interface at the link here.
- Street Address – Used as a street address formatter and parser. Based on the test cases from http://pyparsing.wikispaces.com/file/view/streetAddressParser.py
These packages get the job done for most of the addresses, using Natural Language Processing.
Address Parsing using the Google Maps Geocoding API
In this tutorial, we will show you how to convert a freeform single string address into a structured address with Latitude and Longitude using Google Maps Geocoding API. You can also use this API for Reverse Geocoding. I.e., you can convert geo-coordinates into addresses.
What is Geocoding?
Geocoding is the process of converting addresses such as – “71 Pilgrim Avenue Chevy Chase, Md 20815” into geographic coordinates like – latitude 38.9292172, longitude -77.07120479.
Google Maps Geocoding API
Google Maps Geocoding API is a service that provides geocoding and reverse geocoding for an address. So this Python script is a kind of wrapper for this API.
Each Google Maps Web Service request requires an API key that is freely available with a Google Account at Google Developers Console. The type of API key you need is a Server key.
How to get an API Key
- Visit the Google Developers Console and log in with a Google Account.
- Select one of your existing projects, or create a new project.
- Enable the Geocoding API.
- Create a new Server Key.
- You can restrict requests to a particular IP address, but it is optional.
Important: Do not share your API Key, take care to keep them secure. You can delete an old one and generate a new one if needed.
API Usage Limits
Standard usage: 2500 free requests per day and 50 requests per second
Premium usage: 100,000 requests per day and 50* server-side requests per second
* The default limit can be changed
A Simple Demo
The script below can accept address strings as a CSV, or you can just paste the addresses into a list. The script would output the results as a clean CSV file.
If the embed above does not work, you can get the code from GIST here.
Save the file and run the script in command prompt or terminal as:
Once it completes running, you will get an output in a CSV file data.csv. You can modify the file name from line no. 47. You can also modify the code to supply the file name as a positional argument too.
You can go ahead and modify the lines that read the addresses and writes it, to read from a data pipeline and write it to a database. It’s relatively easy, but beyond the scope of this simple demonstration.
Let us know in comments below how this script worked for you or if you have a better solution.
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