IO error on bulk MXD publishing to ArcGIS Server using Python

[DaveGrolling1]

import arcpy
import os

wrkspc = 'C:/Project/BULK/'
#mxd = arcpy.mapping.MapDocument('BULK_Test.mxd')

con = 'AGSconnectionfile.ags'

for (wrkspc, dirs, files) in os.walk(wrkspc):
    for fl in files:
        if fl.lower().endswith(".mxd"):
            
            mxd = arcpy.mapping.MapDocument(os.path.join(wrkspc, fl))
            # Provide other service details
            service = mxd
            sddraft = 'C:/Project/BULK/' + str(mxd) + '.sddraft'
            sd = 'C:/Project/BULK/' + str(mxd) + '.sd'
            summary = 'BULK_Test'
            tags = 'BULK_Test'

            # Create service definition draft
            arcpy.mapping.CreateMapSDDraft(mxd, sddraft, mxd, 'ARCGIS_SERVER', con, True, "Project", summary, tags)

            # Analyze the service definition draft
            analysis = arcpy.mapping.AnalyzeForSD(sddraft)

            # Print errors, warnings, and messages returned from the analysis
            print "The following information was returned during analysis of the MXD:"
            for key in ('messages', 'warnings', 'errors'):
                print '----' + key.upper() + '---'
                vars = analysis[key]
                for ((message, code), layerlist) in vars.iteritems():
                    print '    ', message, ' (CODE %i)' % code
                    print '       applies to:',
                    for layer in layerlist:
                        print layer.name,
                    print

            # Stage and upload the service if the sddraft analysis did not contain errors
            if analysis['errors'] == {}:
                # Execute StageService. This creates the service definition.
                arcpy.StageService_server(sddraft, sd)

                # Execute UploadServiceDefinition. This uploads the service definition and publishes the service.
                arcpy.UploadServiceDefinition_server(sd, con)
                print "Service successfully published"
            else: 
                print "Service could not be published because errors were found during analysis."

            print arcpy.GetMessages()‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

I have a folder of MXDs and I want to publish all of them in batch to a single ArcGIS Server. I've had success using Python on a single MXD, but when I add a loop into the code so that I can do multiple services at once, I run into errors that I'm unable to troubleshoot. I found the code below on ArcGIS Enterprise site and tried to modify it for batch processing.

I've tried as a standalone script and from within ArcMap 10.7.1. The error:

File "C:\Project\BULK\PublishAGSBulk.py", line 29, in <module>IOError: Operation on file C:\Users\...\Temp\{67337BAB-1DDF-4A39-9FB4-B7C8EF8597B0}\<geoprocessing Map object object at 0x036534A0>.sddraft failed. Unknown error.
‍‍

I am doing this with an active connection to the ArcGIS Server (10.8) in ArcCatalog.

[DanPatterson]

Dave Grolling‌

/blogs/dan_patterson/2016/08/14/script-formatting 

would help the reading of the script and provide line numbers for reference