topic Re: Replace() string function isn't working within Field Calculator and arcpy in Python Questions

Replace() string function isn't working within Field Calculator and arcpy

EugeneDurshpek — Mon, 23 Nov 2015 20:06:50 GMT

I'm trying to figure out what's wrong with my python syntax.

I have an attribute table with 4 fields containing paths to media files. I'm trying to convert the paths so that they behave more like hyperlinks on our network. The existing paths (added to the tables via 3rd party proprietary software) include network drive i.e. M:\GraniteXP\...

I'm trying to use find and replace to replace "M:\GraniteXP" with "\\vancouver.root.local\...\GraniteXP".

I can do this perfectly fine using field calculator in ArcMap as well as Model Builder. However, when I export the model to Python; the script runs (successfully), but the values are not updated. There is not error to tell me what's failing.

Here's a snippet from my script. I do have a MakeFeatureLayer prior to this snippet. (Note: this particular script is trying to change it back to the network drive pathing for testing purposes).

arcpy.SelectLayerByAttribute_management("lyrsdePipeInsp", "NEW_SELECTION", "Photo1 is not null")

arcpy.CalculateField_management("lyrsdePipeInsp", "Photo1", "Replace( [Photo1], \"\\\\vancouver.root.local\\cityapps\\GraniteXP\", \"M:\\GraniteXP\" )", "VB", "")

arcpy.SelectLayerByAttribute_management("lyrsdePipeInsp", "NEW_SELECTION", "Photo2 is not null")

arcpy.CalculateField_management("lyrsdePipeInsp", "Photo2", "Replace( [Photo2], \"\\\\vancouver.root.local\\cityapps\\GraniteXP\", \"M:\\GraniteXP\" )", "VB", "")

arcpy.SelectLayerByAttribute_management("lyrsdePipeInsp", "NEW_SELECTION", "Photo3 is not null")

arcpy.CalculateField_management("lyrsdePipeInsp", "Photo3", "Replace( [Photo3], \"\\\\vancouver.root.local\\cityapps\\GraniteXP\", \"M:\\GraniteXP\" )", "VB", "")

arcpy.SelectLayerByAttribute_management("lyrsdePipeInsp", "NEW_SELECTION", "Video is not null")

arcpy.CalculateField_management("lyrsdePipeInsp", "Video", "Replace( [Video], \"\\\\vancouver.root.local\\cityapps\\GraniteXP\", \"M:\\GraniteXP\" )", "VB", "")

Thanks!

Eugene Durshpek

Re: Replace() string function isn't working within Field Calculator and arcpy

DanPatterson_Retired — Sat, 11 Dec 2021 13:27:11 GMT

a pain with the double slash replacement, you could try replacement with "/"

>>> a = "c:\\path\\subpath\\file.tiff"
>>> b = a.replace("\\","/")
>>> b
'c:/path/subpath/file.tiff'

Re: Replace() string function isn't working within Field Calculator and arcpy

LukeSturtevant — Sat, 11 Dec 2021 13:27:14 GMT

It is a lot faster and easier to code this type of processing with an update cursor.

something like this would work for the code example you gave:

import arcpy
fc = #the path to your feature class
with arcpy.da.UpdateCursor(fc,["Photo1","Photo2","Photo3","Video"]) as update:
     for row in update:
          if row[0] is not None:
                row[0] = row[0].replace("\\vancouver.root.local\\cityapps\\GraniteXP", "M:\\GraniteXP")
         if row[1] is not None:
                row[1] = row[1].replace("\\vancouver.root.local\\cityapps\\GraniteXP", "M:\\GraniteXP")        
         if row[2] is not None:
                row[2] = row[2].replace("\\vancouver.root.local\\cityapps\\GraniteXP", "M:\\GraniteXP")
         if row[3] is not None:
                row[3] = row[3].replace("\\vancouver.root.local\\cityapps\\GraniteXP", "M:\\GraniteXP")
           update.updateRow(row)

Re: Replace() string function isn't working within Field Calculator and arcpy

WesMiller — Mon, 23 Nov 2015 20:32:10 GMT

Not by chance a 64-bit? see below

Caution:

Field calculations with a VB Expression type are not supported on 64-bit products, including ArcGIS Pro, ArcGIS for Desktop—Background Geoprocessing (64-bit) and ArcGIS for Server. To successfully use Calculate Field in these products, expressions should be converted to Python, or in the case of Background Geoprocessing (64-bit), background processing can alternatively be disabled.

Calculate Field—Help | ArcGIS for Desktop

Re: Replace() string function isn't working within Field Calculator and arcpy

EugeneDurshpek — Mon, 23 Nov 2015 21:39:49 GMT

Thank you Luke, I will give this a try. I'm a novice and wasn't sure how to apply the update cursor function to my scenario. I appreciate your quick response.

Eugene D.

Re: Replace() string function isn't working within Field Calculator and arcpy

EugeneDurshpek — Mon, 23 Nov 2015 21:41:01 GMT

Thanks Dan. I will combine your suggestion with Luke's suggestion (below) and will hopefully have best of both worlds.

Eugene D.

Re: Replace() string function isn't working within Field Calculator and arcpy

EugeneDurshpek — Mon, 23 Nov 2015 21:44:02 GMT

Yes, we are running 64-bit OS. Thank you for the link. It's helpful.

Eugene D.

Re: Replace() string function isn't working within Field Calculator and arcpy

Luke_Pinner — Mon, 23 Nov 2015 21:52:45 GMT

You've got your find string and replacement string in the wrong order.

Try:

arcpy.CalculateField_management("lyrsdePipeInsp", "Photo1", r'Replace( [Photo1],"M:", "\\vancouver.root.local")',"VB")

Or:

arcpy.CalculateField_management("lyrsdePipeInsp", "Photo1", r"!Photo1!.replace('M:', r'\\vancouver.root.local')", "PYTHON_9.3")

Re: Replace() string function isn't working within Field Calculator and arcpy

EugeneDurshpek — Mon, 23 Nov 2015 23:07:01 GMT

I am testing this within a session of ArcMap and am getting Runtime Error: Insufficient permissions to edit the feature class [STATE_ID = 207215] which is odd because I can edit and save outside of python.

Re: Replace() string function isn't working within Field Calculator and arcpy

LukeSturtevant — Sat, 11 Dec 2021 13:27:16 GMT

Are you working from an SDE geodatabase? In either case when I see this error I find that opening a da Editor helps:

import arcpy  
workspace = # path to you workspace
fc = # the path to your feature class  
with arcpy.da.Editor(workspace) as edit:
     with arcpy.da.UpdateCursor(fc,["Photo1","Photo2","Photo3","Video"]) as update:  
           for row in update:  
              if row[0] is not None:  
                     row[0] = row[0].replace("\\vancouver.root.local\\cityapps\\GraniteXP", "M:\\GraniteXP")  
              if row[1] is not None:  
                     row[1] = row[1].replace("\\vancouver.root.local\\cityapps\\GraniteXP", "M:\\GraniteXP")          
              if row[2] is not None:  
                     row[2] = row[2].replace("\\vancouver.root.local\\cityapps\\GraniteXP", "M:\\GraniteXP")  
              if row[3] is not None:  
                     row[3] = row[3].replace("\\vancouver.root.local\\cityapps\\GraniteXP", "M:\\GraniteXP")  
              update.updateRow(row)

Re: Replace() string function isn't working within Field Calculator and arcpy

EugeneDurshpek — Sat, 11 Dec 2021 13:27:19 GMT

Thank you Luke;

Yes, I am editing an SDE feature class. I have updated my script (see below) but am now getting a "RuntimeError: cannot open workspace"; I will clean it up once I can get it to work.

import arcpy
workspace = "M:/GIS/Support_Files/DataConnectionsADMIN/SewerVan_NT_SQLGIS1.sde/SewerVan.VANSEWER.SwrPipeInspected"
fc = "SewerVan.VANSEWER.SwrPipeInspected"
with arcpy.da.Editor(workspace) as edit:
    with arcpy.da.UpdateCursor(fc,["Photo1","Photo2","Photo3","Video"]) as update:
        for row in update:
            if row[0] is not None:
                    row[0] = row[0].replace("//vancouver.root.local/cityapps/GraniteXP", "M:/GraniteXP")
            if row[1] is not None:
                    row[1] = row[1].replace("//vancouver.root.local/cityapps/GraniteXP", "M:/GraniteXP")
            if row[2] is not None:
                    row[2] = row[2].replace("//vancouver.root.local/cityapps/GraniteXP", "M:/GraniteXP")
            if row[3] is not None:
                row[3] = row[3].replace("//vancouver.root.local/cityapps/GraniteXP", "M:/GraniteXP")
            update.updateRow(row)

Re: Replace() string function isn't working within Field Calculator and arcpy

LukeSturtevant — Tue, 24 Nov 2015 18:05:46 GMT

I'm not sure if there is an easy way to use the cursors in an ArcSDE geodatabase environment. You could look at this forum here that shows a work around. If you cannot get that figured out you may want to attempt Luke Pinner's suggestion below.

Re: Replace() string function isn't working within Field Calculator and arcpy

EugeneDurshpek — Tue, 24 Nov 2015 18:55:54 GMT

Thanks for reply Luke. I have seen a bunch of suggestions to using the update cursor approach so I was trying to use that first. Unfortunately I haven't been able to get past some workspace and SDE issues.

As far as having my find string and replacement strings backwards; I do realize that. I've been calculating data back and forth while testing my script. At the moment my actual data reflects the successful field calculation with replace() that I ran with Model Builder. I'm trying to change it back with python and then I'll replace the order. (Hope that makes sense).

For whatever reason I just cannot get the VB syntax to work while editing an SDE layer. The script runs, and I get a little message saying that it ran successfully, but my data remains unchanged.

I was finally able to use your syntax suggestion and make it work in a file geodatabase, which I end up appending to SDE to accomplish my final goal.