topic Re: Insert a Zero after a specific number of character in a string in Python Questions

Insert a Zero after a specific number of character in a string

RobSmith — Fri, 03 May 2013 16:33:33 GMT

I have a string field called [PROJECT_NO]. It has 7 characters in the string. Example: 02WG028
We are changing our project number standard to eight characters, so I need to "insert" a zero after the 4th character from the left in the project number.
[ATTACH=CONFIG]24004[/ATTACH]
I have spent almost two whole days trying to figure this out on line with no luck. My head is going to explode!

Thanks in advance for any help.

P.S. this layer is an SDE layer that I am editing using a version.

Re: Insert a Zero after a specific number of character in a string

Anonymous User — Fri, 03 May 2013 17:11:09 GMT

Try this in the field calculator, be sure to set the parser to Python:

Pre-logic code block

def AddZero(field):   new = field[:4] + "0" + field[4:]   return new;

And use this as the expression:

AddZero( !your_fieldname! )

[ATTACH=CONFIG]24010[/ATTACH]

Re: Insert a Zero after a specific number of character in a string

RobSmith — Fri, 10 Dec 2021 22:30:22 GMT

That worked great and now I feel stupid. 🙂

What if I wanted to throw in and if, then testing for the length of the PROJECT_NO string. How would I do that.

Try this in the field calculator, be sure to set the parser to Python:

Pre-logic code block
def AddZero(field):
  new = field[:4] + "0" + field[4:]
  return new;
And use this as the expression:
AddZero( !your_fieldname! )
[ATTACH=CONFIG]24010[/ATTACH]

Re: Insert a Zero after a specific number of character in a string

Anonymous User — Fri, 10 Dec 2021 22:30:25 GMT

You can add an if/then condition very easily with a length test. What kind of conditions were you thinking of adding?

Here is an example of changing where to add the 0:

def AddZero(field):
  # add after 4th char if len == 7
  if len(field) == 7:
    new = field[:4] + "0" + field[4:]  # here is the "then" statement
  elif len(field) == 9:
    new = field[:5] + "0" + field[5:]  # inserts 0 @  'xxxxx0xxxx' (after fifth position)
  return new;

Re: Insert a Zero after a specific number of character in a string

RobSmith — Fri, 10 Dec 2021 22:30:28 GMT

This worked out great. I ended up adding conditions for 6,5,4 & 3 character project numbers. Also I had a condition to just return the field if the project number was greater than 7.

Thanks for all your help. This made my day. I can now relax this weekend. :cool:

You can add an if/then condition very easily with a length test. What kind of conditions were you thinking of adding?

Here is an example of changing where to add the 0:
def AddZero(field):
  # add after 4th char if len == 7
  if len(field) == 7:
    new = field[:4] + "0" + field[4:]  # here is the "then" statement
  elif len(field) == 9:
    new = field[:5] + "0" + field[5:]  # inserts 0 @  'xxxxx0xxxx' (after fifth position)
  return new;

Re: Insert a Zero after a specific number of character in a string

Anonymous User — Wed, 12 Feb 2014 17:02:41 GMT

I am trying to add in punctuation into one of my fields. I saw the response above and tried it, but it only took the last line of code. I also tried adding a "+" in between every one, but that didn't work either. I don't have much of a coding background so I don't really know what else to do.

I am attaching a screen shot of the code I wrote (that doesn't work). I also have a screen shot of a sample area.

Original data- State_PIN
newpin- (I just did this manually, but I am trying to get a field calculator to add in the punctuation for me into the [formatedPIN] field)

Thanks for any help!

Re: Insert a Zero after a specific number of character in a string

JoshuaChisholm — Fri, 10 Dec 2021 22:30:31 GMT

Laura,

You were SO close! Instead of using new= on each line you need to use new+=, otherwise you are replacing the variable new and starting from scratch on each line.

Also, I would take pieces of your string like this field[2:4]. That will grab the second and third characters.

def AddPunc(field):
 new=field[0:2]
 new+="-"+field[2:4]
 new+="-"+field[4:6]
 new+="-"+field[6:9]
 new+="-"+field[9:12]
 new+="-"+field[12:15]
 return new

Let me know how it goes. Good luck!

Re: Insert a Zero after a specific number of character in a string

Anonymous User — Thu, 13 Feb 2014 11:50:46 GMT

Almost!!! It is cutting out the last "-" I need though...

I tried adding another line:

new+="-"+field[15:18]

But that doesn't work. Any ideas?

Thank you!!

Re: Insert a Zero after a specific number of character in a string

Anonymous User — Sun, 12 Dec 2021 15:59:03 GMT

This worked for me:

code block:

from itertools import *

def formatPID(in_pid, delimiter='-', groups=()):
    # groups are how you want to break it up
    in_pid = str(in_pid)
    it = iter(in_pid)
    return delimiter.join(''.join(islice(it, i)) for i in groups)

Expression:

formatPID(!Your_PID_Field!, '-', (2,2,2,3,3,3))

EDIT: sorry, I forgot one group of 2's

Re: Insert a Zero after a specific number of character in a string

JoshuaChisholm — Fri, 10 Dec 2021 22:30:34 GMT

Helle again Laura,

I missed the "." in your screen shot. Try this out:

def AddPunc(field):
 new=field[0:2]
 new+="-"+field[2:4]
 new+="-"+field[4:6]
 new+="-"+field[6:9]
 new+="-"+field[9:12]
 new+="."+field[12:15]
 new+="-"+field[15:18]
 return new

Note if you change [15:18] to [15:], the script will append any extra characters to the end of the new string.

If you're still having problems, make sure you're new field ('formatedPIN') has a length of at least 24 to allow for the new punctuation characters.

Good luck!

Re: Insert a Zero after a specific number of character in a string

Anonymous User — Thu, 13 Feb 2014 13:10:40 GMT

Got it to work, thank you soo much!!!