topic Re: arcpy.mapping replaceDataSource error message in Python Questions

arcpy.mapping replaceDataSource error message

BrodieChisholm — Wed, 24 Apr 2024 18:41:50 GMT

Good day all,

I am trying to automate a process at my work, the script will start by updating the data source for a layer file (.lyr) found at the top of the contents pane in a map document.

The original data source for the layer file is a shapefile and I am trying to update it to a new shapefile found in a workspace/ folder I have assigned the variable "path" to (see screenshot below).

The following screenshot is, from my understanding, a simple way to write the code. I was using the python window in ArcMap for troubleshooting purposes:

As you can see I receive an error message.

I have tried writing this script several different ways, even omitting the map document and pointing straight to the layer file (arcpy.mapping.Layer([path])) but continue to get this error message.

The mapdocument is added ("mxd"), as is the dataframe ("df"), and the layer ("lyr").

Upon reading through past post regarding the .replaceDataSource function, I have seen I am not the first to receive this error message.

I am just starting to write my own scripts and apologize if I reffered to anything incorrectly.

Has anyone figured out how to get past/ correct the error?

Any help with this is greatly appreciated.

Here is the script as I have it written in an IDE, it's not complete but useful for context:

import arcpy, os #Define variables mxd = arcpy.mapping.MapDocument(r"D:\Brodie\Projects\2024\2024 IMT Templates\yyyymmdd_XXX###_OPS_TABLOID_LAND.mxd") df = arcpy.mapping.ListDataFrames(mxd, "")[0] lyr = arcpy.mapping.ListLayers(mxd, "", df)[0] path = r"D:\Brodie\Projects\2023\AFFESIncidentData2023\SUD017_2023\IncidentData\\" #Path to new source data nom = "20230613_1900_SUD017_MAP.shp" #Name of new source data #Update data source for fire perimeter .lyr lyr.replaceDataSource(path, "SHAPEFILE_WORKSPACE", nom) lyr.name = "20230613_1900_SUD017_MAP" #Name of updated layer as it appears in the contents pane #Save mxd under new name mxd.saveACopy(r"D:\Brodie\Projects\2023\AFFESIncidentData2023\SUD017_2023\Projects\20230613_1900_SUD017_OPS_TABLOID_LAND.mxd") print "Script complete"

Re: arcpy.mapping replaceDataSource error message

BlakeTerhune — Wed, 24 Apr 2024 18:13:18 GMT

I haven't done this in ArcMap, but your path doesn't look right. Try removing the two trailing back slashes.

Re: arcpy.mapping replaceDataSource error message

BrodieChisholm — Wed, 24 Apr 2024 18:39:06 GMT

Good afternoon,
Thank you for your response - I tried removing the two back slashes but am receiving the same error.

I added the script as it is written in an IDE to the original post.

Re: arcpy.mapping replaceDataSource error message

BlakeTerhune — Wed, 24 Apr 2024 19:20:20 GMT

Maybe use None for the wildcard parameter instead of an empty string.

df = arcpy.mapping.ListDataFrames(mxd, None)[0] lyr = arcpy.mapping.ListLayers(mxd, None, df)[0]

Re: arcpy.mapping replaceDataSource error message

BrodieChisholm — Wed, 24 Apr 2024 19:43:28 GMT

Good afternoon,

Again, I appreciate your insights and thoughts on a solution.

Unfortunately, I tried using None for the wildcard parameter and received the same error message.

I would do this in Pro but the organisation I work for is still using ArcMap for certain processes - so trying to get this to work in ArcMap/ Python 2.7.

Thanks again

Re: arcpy.mapping replaceDataSource error message

Tom_Laue — Wed, 24 Apr 2024 19:54:45 GMT

I've used variations of this script:

Updating and fixing data sources with arcpy.mapping

import arcpy mxd = arcpy.mapping.MapDocument(r"C:\Project\Project.mxd") for lyr in arcpy.mapping.ListLayers(mxd): if lyr.supports("DATASOURCE"): if lyr.dataSource == r"C:\Project\Data\Parcels.gdb\MapIndex": lyr.findAndReplaceWorkspacePath(r"Data", r"Data2") mxd.saveACopy(r"C:\Project\Project2.mxd") del mxd

Re: arcpy.mapping replaceDataSource error message

BrodieChisholm — Thu, 25 Apr 2024 15:45:01 GMT

Good morning Tom,

Thank you for your reply, I do not know if this will work as the name of the new data is not the same as the previous - the findAndReplaceWorkspacePath looks for data of the same name in a new path (from my understanding).

Also in line 6 - what are you setting the 2 "Data" variables to ?

Thanks again

Re: arcpy.mapping replaceDataSource error message

jinte0107 — Tue, 02 Sep 2025 08:14:01 GMT

Hello, I am Jin-tae Kim
I reviewed the information you shared and thought it might be helpful, so I’m leaving a reply.

Since some time has passed, you may have already resolved the issue in another way. If so, it would be great if you could share your solution as well.

As far as I have seen, when working with a shapefile, the data source specified in the arcpy.layer.replaceDataSource function should not include the file extension.
I recommend removing the extension and trying again.