Query UK Postcode (Town, Region, Country) (2855 Postcodes)

[IndigoFuzz]

Hi all,

Thought I might share this piece of code I've written to aid me in data extraction in a professional environment.

The purpose of the code is to be able to determine which Country a UK postcode is listed in (to assist in a marketing campaign).

Find the source here: https://github.com/IndigoFuzz/PureBasic ... stcode.pbi


An example of use:

Code: Select all

IncludeFile "include/postcode.pbi"

; Create List of Test Postcodes
NewList ToCheck.s()
AddElement(ToCheck()) : ToCheck() = "CF5 1AB" 
AddElement(ToCheck()) : ToCheck() = "NP2 1AB"
AddElement(ToCheck()) : ToCheck() = "ST20 1AB"
AddElement(ToCheck()) : ToCheck() = "BT1 1AB"
AddElement(ToCheck()) : ToCheck() = "DT4 1AB"

; Initialise Postcode Query Module
PostCode::Initialise()

; Query Postcodes
ForEach ToCheck()
  Debug "Checking Postcode: " + ToCheck()
  Debug " - Country: " + PostCode::CountryStr(PostCode::GetCountry(ToCheck()))
  Debug " - Region: " + PostCode::GetRegion(ToCheck())
  Debug " - Town: " + PostCode::GetTown(ToCheck())
  Debug ""
Next

; - Uninitialise Postcode Module
PostCode::Release()

Hope someone finds it useful

[IdeasVacuum]

Neat code. Can I ask why you didn't use a database? There are approx 43,000 ZIP Codes in the USA.

[bosker]

Interesting code. Thanks for posting - but I found a bug.
For example, if you are searching for (say) NP22, it will actually match with NP2.
The problem lies in the Get... functions, with this line..

Code: Select all

 If Left(PostCode$, Len(this\pcodes()\prefix)) = this\pcodes()\prefix

This is because the length of the prefix(which may be shorter) is used to match.

I believe it can be fixed by changing the first 3 lines of the Get... functions to..

Code: Select all

    PostCode$ = UCase(StringField(PostCode$, 1, " "))
    ForEach this\pcodes()
      If PostCode$ = this\pcodes()\prefix

[the.weavster]

Where did you get those codes from?

The CB4 code covers a large are of Cambridge from Huntingdon Rd to the A14 but your list returns Impington which is a small village outside of Cambridge. In reality Impington is a CB24 code.
For CB25 you're returning Lode which is probably the smallest village within that area.
For CB5 your list returns Stow-cum-Quy but Stow-cum-Quy is really in CB25 with Lode, again CB5 includes a large part of the city of Cambridge from Jesus Green to out beyond the airport.
CB6 is Downham? Downham is a parish not a village, town or city.

These are just the ones I know off the top of my head

I hope the rest of your list is in better condition than the details you have for the Cambridge area.

[IndigoFuzz]

Thanks for the comments folks

@bosker - Yes~ I did realise that after putting it in to practice. When I can I'll update the code to introduce the fix

@IdeasVacuum - Using a Database is always going to be the better solution, but with this being such a specific application, it was a lot quicker to just scratch it together in a single include file.

@the.weavster - It was a freely gained list of postcodes so I can't vouch for the accuracy to Towns and and Regions sadly The application is purely for establishing postcode to country, but as the region and town data was available in the CSV list I acquired, I quickly put in the functionality to retrieve the values.