using web services other timesthe vendor wants increased assurance of the source of the requests and so they expect you to send cryptographically signed messages using shared keys and secrets very common technology that is used to sign requests over the internet is called oauth you can read more about the oauth protocol at www oauth net thankfully there are number of convenient and free oauth libraries so you can avoid writing an oauth implementation from scratch by reading the specification these libraries are of varying complexity and have varying degrees of richness the oauth web site has information about various oauth libraries glossary api application program interface contract between applications that defines the patterns of interaction between two application components elementtree built-in python library used to parse xml data json javascript object notation format that allows for the markup of structured data based on the syntax of javascript objects soa service-oriented architecture when an application is made of components connected across network xml extensible markup language format that allows for the markup of structured data application google geocoding web service google has an excellent web service that allows us to make use of their large database of geographic information we can submit geographical search string like "ann arbormito their geocoding api and have google return its best guess as to where on map we might find our search string and tell us about the landmarks nearby the geocoding service is free but rate limited so you cannot make unlimited use of the api in commercial application but if you have some survey data where an end user has entered location in free-format input boxyou can use this api to clean up your data quite nicely when you are using free api like google' geocoding apiyou need to be respectful in your use of these resources if too many people abuse the servicegoogle might drop or significantly curtail its free service you can read the online documentation for this servicebut it is quite simple and you can even test it using browser by typing the following url into your browsermake sure to unwrap the url and remove any spaces from the url before pasting it into your browser the following is simple application to prompt the user for search stringcall the google geocoding apiand extract information from the returned json