topic Re: Field calculator: add space before last 3 characters? in Python Questions

Field calculator: add space before last 3 characters?

TheodoreF — Thu, 09 Nov 2017 16:56:26 GMT

Hi,

I have a Postcode point file where all the postcodes are formatted with no space. ie: AB109XY

I've made another blank text field to contain all the postcodes but with a space instead. ie. AB10 9XY

The space will always come before the last 3 characters of the string.

Can someone provide me with a VB or python code to enter into ArcMap field calculator?

Thanks.

Re: Field calculator: add space before last 3 characters?

XanderBakker — Fri, 10 Dec 2021 22:39:20 GMT

You could use the Python syntax and use this function:

def corrPC(postcode):
    if len(postcode) == 7:
        return postcode[:4] + " " + postcode[4:]
    else:
        return postcode‍‍‍‍‍‍‍‍‍‍

Re: Field calculator: add space before last 3 characters?

TheodoreF — Thu, 09 Nov 2017 17:30:40 GMT

Thanks. That's added a space for every 7 character postcode.

However, some postcodes are only 6 characters in lenght. Guess I'll just change the 7 to 6...

Re: Field calculator: add space before last 3 characters?

TheodoreF — Thu, 09 Nov 2017 17:33:02 GMT

Ah actually had to change the 7 to 6 and the last 4 to 3

thanks!

Re: Field calculator: add space before last 3 characters?

XanderBakker — Fri, 10 Dec 2021 22:39:23 GMT

In that case you could have done this:

def corrPC(postcode):
    if len(postcode) in [6, 7]:
        return postcode[:len(postcode)-3] + " " + postcode[len(postcode)-3:]
    else:
        return postcode
‍‍‍‍‍

Be careful not to rerun the expression, since a postcode with original length of 6 will turn 7 and get an additional space.

Re: Field calculator: add space before last 3 characters?

TheodoreF — Fri, 10 Dec 2021 22:39:25 GMT

Ok it turns out there are a few 5 character postcodes.

Like: M73NE

Would I now need to make it:

def corrPC(postcode):
    if len(postcode) in [5, 6, 7]:
        return postcode[:len(postcode)-3] + " " + postcode[len(postcode)-3:]
    else:
        return postcode

Re: Field calculator: add space before last 3 characters?

XanderBakker — Thu, 09 Nov 2017 17:53:21 GMT

Yes (if you still need to insert the space before the last three characters)

Re: Field calculator: add space before last 3 characters?

DanPatterson_Retired — Fri, 10 Dec 2021 22:39:28 GMT

Canada eh?

postcodes = ['ABC123', 'DEF45', 'GHI']
for pc in postcodes:
    print('{} {}'.format(pc[:3], pc[3:]))
    
ABC 123
DEF 45
GHI ‍‍‍‍‍‍‍

so all you need in the field calculator is

'{} {}'.format(!pc![:3], !pc![3:])  # --- python parser, 'pc' is the field
# ---- or 
'{} {}'.format(!pc![:3], !pc![3:]).strip()  #--- to strip leading trailing spaces‍‍‍

Re: Field calculator: add space before last 3 characters?

JayantaPoddar — Thu, 09 Nov 2017 20:20:07 GMT

Check the following expression in Python Parser.

(!POSTCODE! [:(len( !POSTCODE!)-3)] + " " + !POSTCODE! [(len( !POSTCODE!)-3):]‍).strip()‍