How do I replace the first character of a string using calculate field in ArcGIS Pro?

[JoeLivoti]

Pretty simple question I'm sure for the Python people out there. I have a field, FACILITY ID, that is populated as string values as 00001,00002, 00003, and so on. All values in the field are 5 characters long. I want to change the first number in to a 1 so the values of the field look like 10001, 10002, 10003, etc. I'm pretty sure i should use the .replace(), but I cannot format it correctly. Any advice would be very welcome. Thank you.

[DanPatterson · Accepted solution]

"1" + !YourField![1:]‍

python parser and YourField is the field that contains the original.

It is best to do calculations in a new field in case things go real bad.

You can copy them back into the original later

[JoeLivoti]

Dan,

Thank you that worked perfect. How would I augment that to change a different value in the string, say the second value to a 5? Again thank you!!!!

[JoshuaBixby]

Although you asked a follow-up question, Dan addressed your first question.  Please mark his response as Correct to close out the question.

[DanPatterson]

"15" + !YourField![2:]

or if you just mean the 2nd value, leaving the first along

!YourField![:1] + "5" +!YourField![2:]

[JoeLivoti]

Thank you Dan!! The second one was exactly what i needed!

[DanPatterson]

no problem