topic Re: How do you write expression in Label field to replace text with numbers ? in Mapping Questions

How do you write expression in Label field to replace string with values ?

DEAF_PROBERT_68 — Fri, 15 Jan 2016 22:49:13 GMT

Hi,

Here I have a field that has ID which show each road numbers ie: 200.B, 787, JEF-83N and they are all mixed up..

How do I write to replace them with text with just numbers

Ie: 2000. B to 200

JEF-83N to 83N

I am stuck here ?????

This is to display road numbers to show numbers within the Symbol Like this , ,

I'm using Label expression with VBscrpit but can take JScrpit or Python ....

Thanks !!!

Re: How do you write expression in Label field to replace text with numbers ?

ChrisDonohue__GISP — Fri, 15 Jan 2016 22:56:55 GMT

Conceptually, the first idea that comes to mind would be to cast them to an integer field, which would theoretically drop out all the characters. I'll have to tinker with that....

Also, I'm fairly sure there is a way to do this in Python, but don't know the specifics. I'm sure there will be several replies soon here given the high level of Python skill on GeoNet.

Chris Donohue, GISP

Re: How do you write expression in Label field to replace text with numbers ?

DarrenWiens2 — Sat, 11 Dec 2021 14:48:29 GMT

You need to rephrase your question to be as stupid as a computer. You're not looking for "numbers", you're looking for something that meets a set of rules that you've made up.

For example, "if the road label contains a hyphen, I only want the characters after the hyphen"

>>> string = 'JEF-83N'
... if '-' in string:
...     road_number = string.split('-')[1]
... print road_number
... 
83N

...or "if the road label contains a period, I only want the characters before the period"

>>> string = '2000.B'
... if '.' in string:
...    road_number = string.split('.')[0]
... print road_number
...
2000

^ I assume in your example "2000. B to 200" you meant 2000.

Re: How do you write expression in Label field to replace text with numbers ?

ChrisDonohue__GISP — Fri, 15 Jan 2016 23:10:58 GMT

Robert - do you have other examples of the "before" and "after"? I ask as in one of the two examples you provided there is still a non-number in the desired result:

EF-83N to 83N

What Darren Wiens suggested looks like it will do the trick for some of this, but I suspect there will be a bit more complexity that may require some other Python functions. If you have a sample set of the start/desired result, that will help in figuring out the exact functions needed. Essentially, as Darren mentions, you need to come up with the "rules". Once the "rules" are assembled, the next step will be to come up with the functions that accomplish them.

Also, my cast idea didn't pan out.

Chris Donohue, GISP

Re: How do you write expression in Label field to replace text with numbers ?

DanPatterson_Retired — Sat, 11 Dec 2021 14:48:32 GMT

Definitely the rules...

Not a solution for all cases!!!!

>>> import string
>>> numbers = string.digits
>>> a = "JEF-83N"
>>> b = "".join([i for i in a if i in numbers])
>>> b
'83'

Although it looks like a solution, it will fail if a = "JEF-83N1" because you will probably not want the appending 1. Also b is returned as a string...is that what you want ? probably.

So the points that Chris and Darren are trying to make, is that you need to establish the rules. The point I will make, is that it may be easier to provide a two-step solution rather than finding the "panacea script".

Re: How do you write expression in Label field to replace text with numbers ?

DEAF_PROBERT_68 — Sat, 16 Jan 2016 02:04:30 GMT

Yes correct 2000.B to 2000.

Re: How do you write expression in Label field to replace text with numbers ?

DEAF_PROBERT_68 — Sat, 16 Jan 2016 23:43:50 GMT

I'll try that and see if that works. Wish me luck !

Re: How do you write expression in Label field to replace text with numbers ?

ChrisDonohue__GISP — Sun, 17 Jan 2016 01:41:25 GMT

This is GIS - what could possibly go wrong?

Chris Donohue, GISP

Re: How do you write expression in Label field to replace text with numbers ?

DEAF_PROBERT_68 — Sun, 17 Jan 2016 19:26:07 GMT

Last Friday, I was probably not thinking correctly. I came down a cold and wasn't thinking so when I wrote this post before I went home.

So, I haven't done anything since then. I will let you know how that works.

Thanks all.

P.S. Is that related to set of rules or related to label expression ?

I am going to do this anyway near in the future...

Re: How do you write expression in Label field to replace text with numbers ?

RobertBorchert — Mon, 18 Jan 2016 19:34:57 GMT

To much thought going into this thread.

Do it the simple way.

Simply create a new string column to label from. Use a string because an integer column will always have at least a zero.

Go into MS Access and calculate then number column from the name column

Val([Roads]![STR_NAME])

Then simply find and replace a whole cell values of Zero with a <Null>

Re: How do you write expression in Label field to replace text with numbers ?

MichaelRobb — Mon, 18 Jan 2016 20:56:27 GMT

As already mentioned:

Based on the i.e. supplied. JEF-83N to 83N How is 83N a numeric value ? (just a number would be 83, excluding the N.

Re: How do you write expression in Label field to replace text with numbers ?

MichaelRobb — Mon, 18 Jan 2016 21:06:38 GMT

My thoughts on this:

Simply creating fields to satisfy labeling is a DBAs worst nightmare... as well as a developers worst nightmare and an architecture guys worst nightmare. Any process used for updating the data then need to handle these 'one off's'. And then How many one offs are to be made? There is no scalablity with this. Its an immediate fix that can make a huge mess in a hurry. The data should be clean or in this case, if need be, expressions can be made.. its not hard.

As mentioned above... Rules need to be understood.. then a simple expression codeblock can be derived... and it will work.

Where was it mentioned the poster was using a Personal Geodatabase?

Re: How do you write expression in Label field to replace text with numbers ?

DEAF_PROBERT_68 — Mon, 18 Jan 2016 22:13:19 GMT

Michael,

I didn't attribute them. The layer was done by one of the Forest Service where I work for assigned the numbers and I believe they were on the forest road or private load. I haven't looked at them yet...

I had to create a map for one of our Ranger District who need me to make map of a Locator Map of their district ranger where their campground is and the layer I had had multiple road names there. I will work on them tomorrow ( Today is a holiday for us to take the day off ).

So the field column I have for the roads has many multiple road numbers like I mention at the top. So, what I am trying to do is show the symbol for each road that I have on the roads. Some of them have private roads, Forest road, Interstate, State and Federal roads. That is why I asked because the number and strings are mixed.

I hope I explained in more clarify this time that I posted from last Friday.

Re: How do you write expression in Label field to replace text with numbers ?

MichaelRobb — Mon, 18 Jan 2016 22:18:06 GMT

Though there is a discrepancy with you asking for Just numbers but in your example, you included a character that is clearly not a number...

Below works... I used a Regular Expression pattern to basically remove ANYTHING except digits. But this expression can be tailored to anything you would like.

Use this in your label Expression:

1. Check Advanced

2. Parcer = VBScript

TEST = the Field in the attribute table to get string

Function FindLabel ([TEST])

Dim strInputString

Dim strOutputString

strInputString = [TEST]

Dim objRegEx

set objRegEx = createobject("VBScript.RegExp")

objRegEx.Global = True

objRegEx.Pattern ="[^0-9]"

strOutputString = objRegEx.Replace(strInputString,"")

'Return string for Labeling

FindLabel = strOutputString

End Function

Re: How do you write expression in Label field to replace text with numbers ?

MichaelRobb — Mon, 18 Jan 2016 22:28:38 GMT

HI Robert.

Regardless if you attributed them or not, the statement you said quote "How do I write to replace them with text with just numbers" and then your example includes you wanting to have an output of 83N. This is what was confusing.

Let me clarify:

Are you asking to have an output of labels of JUST NUMBERS? so then it would only be 83.

If you want an output of Labels of 83N in the example, then your statement of asking JUST NUMBERS is incorrect.

If you want a label expression to handle anything in a field to only label with Digits only then Check out my post reply to your original Post.

If you are looking at 'changing the original field so for a field calculator.. it is also the same idea, but slightly different... but then that comes to a challenged question of 'why are you creating fields to create labels?'...A separate discussion.

Re: How do you write expression in Label field to replace text with numbers ?

DEAF_PROBERT_68 — Mon, 18 Jan 2016 23:34:34 GMT

All right, so saying numbers isn't the right word for writing an expression. Instead of numbers should I just say values , or string ?

Re: How do you write expression in Label field to replace text with numbers ?

DanPatterson_Retired — Mon, 18 Jan 2016 23:46:15 GMT

as in the many examples that have been given, you are trying to extract numbers from a string...

"83" or '83' or 83N are strings. The first 2 are overt because they are enlosed in quotes. 83N has to be a string because you cannot have a number beside test because in programming world they are different objects. As soon as you have an address, you are working with strings. ....so it is terminology that is the key and the many possibilities provide solutions. I will reiterate again, as I do on these topics, ... don't wait for the "tool" that will work in all cases. Breaking a problem down into its components, or exceptions will expedite a faster resolution by using several different tools rather than trying to find the all encompassing solutions. I am sure that your whole problem could have been resolved by using several little "solutions" rather than waiting for the "ONE" solution that will work in all cases.