topic Re: Learning Python- Needing help with If/Then Field Calculator Script in Python Questions

Learning Python- Needing help with If/Then Field Calculator Script

Gtech301 — Tue, 09 Jul 2024 17:50:44 GMT

Hello! I am very very new to Python and am needing help creating a script for Field Calculator and am having trouble finding an online resource- hoping someone here could help me! I created a script that populates a new field based off of existing attributes in an existing field but am needing to add a caveat that if another case is true, then this other condition supersedes all other conditions.

ie I currently have something along the lines of:

def Reclass(field1):

if (field 1=='x'):

return "1"

if (field 1 =='y'):

return "2"

else:

return "3"

But I want to add something that says that no matter what is in field 1, if field 2 == y, return 4: a condition to supersede all the other conditions.

Thanks in advance!

Re: Learning Python- Needing help with If/Then Field Calculator Script

AlfredBaldenweck — Tue, 09 Jul 2024 17:57:51 GMT

Should be straightforward.

Try something like this:

def reclass(field1, field2): # Check field2 and then immediately exit if it works. if field2 == "y": return 4 # Start checking field1. if field1 == "x": return "1" elif field1 == "y": return "2" else: return "3"

Re: Learning Python- Needing help with If/Then Field Calculator Script

BlakeTerhune — Tue, 09 Jul 2024 17:58:15 GMT

The conditions are evaluated in order so put the most important one first and use elif for the other conditions. You'll also need to update the parameters in your function to accept Field2.

# Expression Reclass(!Field1!, !Field2!) # Code Block def Reclass(field1, field2): if field2 == "y": return "4" elif field1=="x": return "1" elif field1 =="y": return "2" else: return "3"

Re: Learning Python- Needing help with If/Then Field Calculator Script

Gtech301 — Tue, 09 Jul 2024 18:09:04 GMT

Thanks, really appreciate the help!

Re: Learning Python- Needing help with If/Then Field Calculator Script

Gtech301 — Tue, 09 Jul 2024 18:09:14 GMT

Thank you!