Latest Contributions by RichardFairhurst

These two add-ins are the set of search tools I created for Riverside County. If you download the County's data and reconnect the data sources these tools can search for various items.  The map contains the minimum search tool set up requirements.  Any other layers can be added to the map without affecting the tools as long as the search layer names are not changed.  I also have included a layer file to add to your existing maps as an alternative to using the Base map; however, in addition to the layer the Base map includes layout objects that work in conjunction with the tools to display a Title and scale bar that best match the tool search results.  Finally, there is an instruction guide for using the Search for Road Segment tool Word 2007 document attached.  The Add-Ins work for ArcGIS 10.6 or above. If you want a version of the search tools for ArcGIS Pro versions 2.8.0 to 2.9.x you can download it from my Riverside County ArcGIS Pro Search Tool Add-In Blog. How to Install the Search Tools   For users of my search tools who currently see my tools in ArcMap:  If you are currently using my search tools in ArcMap and you want to update them to the latest version, you just need to refresh the Add-Ins by doing the following:   Close ArcMap if it is open. Save the attached SearchFormsNew1.zip file to your desktop and double click it. Unzip the files and double click the SearchFormsNew1.esriAddIn file. Click the Install Add-in button at the bottom of the Esri ArcGIS Add-In Installation Utility dialog. Click the OK button on the Esri ArcGIS Add-In Installation Utility dialog that says the Installation succeeded. Save the attached SearchRoadSegment.esriAddIn.zip file to your desktop and double click it. Unzip the files and double click the SearchRoadSegment.esriAddIn file. Click the Install Add-in button at the bottom of the Esri ArcGIS Add-In Installation Utility dialog. Click the OK button on the Esri ArcGIS Add-In Installation Utility dialog that says the Installation succeeded. You should now be able to open ArcMap with a map containing the appropriate Search layers and use the tools.   For new users of my search tools or those with a new installation of ArcMap - To install the search tools for a new or fresh full installation do the following:   Close ArcMap if it is open. Save the attached SearchFormsNew1.esriAddIn.zip file to your desktop and double click it. Unzip the files and double click the esriAddIns. Click the Install Add-in button at the bottom of the Esri ArcGIS Add-In Installation Utility dialog. Click the OK button on the Esri ArcGIS Add-In Installation Utility dialog that says the Installation succeeded. Save the attached SearchRoadSegment.esriAddIn.zip file to your desktop and double click it. Unzip the files and double click the esriAddIns. Click the Install Add-in button at the bottom of the Esri ArcGIS Add-In Installation Utility dialog. Click the OK button on the Esri ArcGIS Add-In Installation Utility dialog that says the Installation succeeded. Open ArcMap without loading a document. Expand the Customize menu on the main menu bar. Click Customize Mode in the drop down menu. Click the Commands tab in the Customize dialog window. Towards the top of the Categories list click the Add-In Controls Category. Click and Drag the Search Road Segments icon onto your main toolbar and drop it onto the toolbar. Scroll to the bottom of the Categories list and click the Transportation Category. Click and Drag the Launch Forms icon onto your main toolbar (probably next to the Identify tool) and drop it onto the toolbar. Close the Customize Dialog. Load a map that has the layers that have names beginning with the word “Search” in them.  The attached Search Layers.lyr file and BAse Search Tool Map.mxd area available for those who do not have access to the internal Riverside County Transportation and Land Management standard maps. Click the Launch Forms button or the Search Road Segments button on your toolbar and perform a search.   Message was edited by: Richard Fairhurst on November 22, 2014, December 3, 2014, and December 8, 2014 Updated the SearchFormsNew.esriAddIn to include a Point Address search tool and modified the Base Search Tool Map.mxd to include a Search Address Points layer to support the tool.  Added a separate layer file as an alternative way to add the search capabilities to existing maps.  Indicated the version of ArcMap supported by the Add-Ins. 12/3 - Corrected dialog behavior for APN Address Search tool.  12/4 - Created a Search for Parcel Owner tool.  12/8 - Added Installation Instructions and usage instructions for the Search for Road Segment tool.   Message was edited by: Richard Fairhurst Fixed a minor measure unit conversion bug on the interface,   Message was edited by: Richard Fairhurst - January 28, 2016 5:33 P.M. PST - Updated the SearchRoadSegment.esriAddin Tool to work with ArcMap 10.3   Message was edited by: Richard Fairhurst - August 23, 2016 9:54 A.M. PST - Updated the SearchFormsNew.esriAddin Tool to handle Address searches when the Owner1 fields are Null and altered the CaseReporter button to make the local path based on the user name.  The SearchFormsNew.esriAddIn may require ArcMap 10.3 now.   Message was edited by: Richard Fairhurst - August 25, 2016 7:15 A.M. PST - Updated the SearchRoadSegment.esriAddin Tool to fix bug in the Intersection Search tool that caused the Primary name to change when user selected and started typing over the Secondary Name, so that now the Secondary Name is edited as expected.   Message was edited by: Richard Fairhurst - January 10, 2018 11:40 AM PST - I attached a 10.5.1 version of the main search tools named SearchFormsNew1.zip.  If you have ArcMap 10.5.1 or higher installed, use the tools in the SearchFormsNew1.zip version instead of the tool in  SearchFormsNew.esriAdding.zip version.  The latest tool fixes bugs created as a result of RCIT changing the Parcel_Assessors feature class so that it stores Null values in text fields instead of "" values.   Message was edited by: Richard Fairhurst - January 11, 2018 08:55 AM PST - I replaced the SearchFormsNew1.zip file with a revised version that replaced the LMS Cases search with the PLUS Cases search.  The PLUS Cases search needs a layer called Search PLUS Cases that has data coming from the PLUS_ACTIVITIES feature class or a derivative subset feature class extracted from PLUS_ACTIVITIES with a field called CASE_ID.   Message was edited by: Richard Fairhurst - March 14, 2018 10:26 AM PST - I added the SearchRoadSegment1.zip file with a revised version that updates the Search Road Segment tool for ArcMap 10.5.   Message was edited by: Richard Fairhurst - July 2, 2018 11:28 AM PST - I updated the SearchFormsNew1.esriAddin.zip file with a revised version of the Search Plus Cases tool that allows case numbers to have up to 25 characters..   Message was edited by: Richard Fairhurst - January 7, 2019 04:47 AM PST - I updated the SearchFormsNew1.esriAddin.zip file with a revised to work when searching for intersections with apostrophes in one or both of the street names. Message was edited by: Richard Fairhurst - March 15, 2022 12:05 PM PST - I replaced the SearchRoadSegment1 zip file with the SearchRoadSegment1 (2).zip file to use current DFS path name for layer files.   Message was edited by: Richard Fairhurst - June 28, 2022 03:57 PM PST - I updated the SearchFormsNew1.esriAddin.zip file with a revised to work when searching for PARCELS_CREST as the Search_Parcels layer and the CREST_ASSESSEE table for property owners in the Search by Address and Search by Owner tools. Message was edited by: Richard Fairhurst - September 20, 2022 04:45 PM PST - I updated Included a link to my blog for an ArcGIS Pro version of the Search Tools. Message was edited by: Richard Fairhurst - May 16, 2023 11:15 AM PST - I corrected an error that prevented the search forms from appearing if the CREST_ASSESSEE table did not exist in the map, changed the GDB_PUB Server where the old server was referenced and compiled for ArcMap 10.8. ... View more

The Problems with Using the Field Calculator, Join and Summary Statistics tools   The field calculator is a great tool and easy to set up, but it has several limitations that can seriously slow down scripted routines when you need to do a lot of data manipulation with large data sets.  The most obvious limitation is that only one field can be calculated at a time.  This often means having to process every record in the feature class multiple times in order to update several fields.  If you need to do data transfers between feature classes using a join it is critical to index the join field in both feature classes to avoid calculations that take forever to process, and even then the speed is significantly slower when a join is involved.  Also, if you actually need to use multiple fields to create a join that correctly matches records between feature classes your only option is to create a new field in both feature classes that concatenates those field values to make a join that works.  Also, often before these joins can be created a summary table has to be created, which takes more time.   Fortunately if you have ArcGIS Desktop 10.1 or later there is an alternative that can speed scripts like this up dramatically and make data transfers between feature classes both flexible and incredibly fast.  The solution is to replace the field calculator with one or more data access cursors (da cursors) and joins and creating summary tables with one or more python dictionaries built using a da SearchCursor.   Using a da UpdateCursor to Replace a Field Calculation within a Single Feature Class:   Below is a simple script that will use a da UpdateCursor on a feature class to fill in a URL field with a hyperlink that is built using a value taken from another field.  The strftime method is used to print out the time when the script starts and the time when it finishes.  To adapt this script to your own data you only need to change the Feature Class path and name in line 7, the field names in the field list in line 9 and the URL string in line 14.  This should perform about 7 times faster than a similar field calculation.   from time import strftime print( "Start script: " + strftime("%Y-%m-%d %H:%M:%S")) import arcpy updateFC = r"C:\Path\FeatureClass" updateFieldsList = ["URLField", "ValueField"] # Example fields that will build a URL based on another field with arcpy.da.UpdateCursor(updateFC, updateFieldsList) as updateRows: for updateRow in updateRows: # updateRow[0] is the URL field and updateRow[1] is the value field updateRow[0] = r" http://pic.asrclkrec.com/view_ParcelMaps.aspx?ParcelNumber= " + str(updateRow[1]) updateRows.updateRow(updateRow) print( "Finished APN_MAP field update: " + strftime("%Y-%m-%d %H:%M:%S")) ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Using a da UpdateCursor to Replace Several Field Calculations within a Single Feature Class:   Now lets say that we actually need to process 2 more field calculations to complete the update of this feature class.  One calculation needs to add two other fields together, and the other needs to convert the values in a field from capitalized values to title case values.  So if there are 100K records, then all of those records have to be calculated 3 times.   All of this can be handled in a single pass of one da UpdateCursor through the 100K records.  Because the records only have to changed once and the addition of more fields for the UpdateCursor to read or calculate takes very little additional time to process, the speed gain over 3 field calculations is much faster that the previous script.  As a result, the more field calculations you can replace with a single pass of a da UpdateCursor, the more dramatically the speed of the script will improve.   Below is the script that can do all three field updates (assume that there are no Null values in the fields being added together or changing case).  To use this script with your own data you still only need to change lines 7, 9, and 14 (optionally change the calculations in lines 16 and 18).   from time import strftime print( "Start script: " + strftime("%Y-%m-%d %H:%M:%S")) import arcpy updateFC = r"C:\Path\FeatureClass" updateFieldsList = ["URLField", "ValueField", "SumField", "NumberField1", "NumberField2", "TitleCaseField"] # Example fields that will build a URL based on another field with arcpy.da.UpdateCursor(updateFC, updateFieldsList) as updateRows: for updateRow in updateRows: # updateRow[0] is the URL field and updateRow[1] is the value field updateRow[0] = r" http://pic.asrclkrec.com/view_ParcelMaps.aspx?ParcelNumber= " + str(updateRow[1]) # updateRow[2] is the Sumfield and updateRow[3] and updateRow[4] are the NumberField1 and NumberField2 fields. updateRow[2] = updateRow[3] + updateRow[4] # updateRow[5] is the TitleCaseField that is having its Capitalized values replaced with Title Case values. updateRow[ 5 ] = updateRow[ 5 ].title() updateRows.updateRow(updateRow) print( "Finished APN_MAP field update: " + strftime("%Y-%m-%d %H:%M:%S")) ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Using a Python Dictionary Built using a da SearchCursor to Replace a Join Connecting Two Feature Classes:   Another common data manipulation involves joining one feature class to another in order to transfer values from the Joined feature class to the Target feature class using the Field Calculator.  However, features loaded into a Python Dictionary using a Search Cursor are much faster at matching join field values in one feature class to another than a Join.  Combined with using a da UpdateCursor to replace the Field Calculator, the speed of these kinds of data manipulations can be even more dramatic than data manipulations on a single feature class.   Example 1 - Transfer of a Single Field Value between Feature Classes   Below is the code required to transfer the value of one feature class to another based on a common join value in another field.  To adapt this script to your own data change lines 7 and 14 to the path and name of the source (Join) and update (target) Feature Class to match the feature classes you would normally join, change lines 9 and 16 to replace the field list with the name of the Join field and the name of the field being transferred.   from time import strftime print( "Start script: " + strftime("%Y-%m-%d %H:%M:%S")) import arcpy sourceFC = r"C:\Path\SourceFeatureClass" sourceFieldsList = ["JoinField", "ValueField"] # Use list comprehension to build a dictionary from a da SearchCursor valueDict = {r[0]:(r[1:]) for r in arcpy.da.SearchCursor(sourceFC, sourceFieldsList)} updateFC = r"C:\Path\UpdateFeatureClass" updateFieldsList = ["JoinField", "ValueField"] with arcpy.da.UpdateCursor(updateFC, updateFieldsList) as updateRows: for updateRow in updateRows: # store the Join value of the row being updated in a keyValue variable keyValue = updateRow[0] # verify that the keyValue is in the Dictionary if keyValue in valueDict: # transfer the value stored under the keyValue from the dictionary to the updated field. updateRow[1] = valueDict[keyValue][0] updateRows.updateRow(updateRow) del valueDict print( "Finished script: " + strftime("%Y-%m-%d %H:%M:%S")) ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Example 2 - Transfer of Multiple Field Values between Feature Classes where there is a 1:1 Match between Field Sets   Just like the Field Calculator the more fields being transferred from one feature class to the other, the more your script will speed up.  If the transfer is a simple field for field transfer then the transfer fields can be handled in a for loop.  Below is an example of a transfer of 5 matching fields between two feature classes.  To adapt this code to your data you should again change the feature classes in lines 7 and 14 and the field lists in lines 9 and 16.   from time import strftime print( "Start script: " + strftime("%Y-%m-%d %H:%M:%S")) import arcpy sourceFC = r"C:\Path\SourceFeatureClass" sourceFieldsList = ["JoinField", "ValueField1", "ValueField2", "ValueField3", "ValueField4", "ValueField5" ] # Use list comprehension to build a dictionary from a da SearchCursor valueDict = {r[0]:(r[1:]) for r in arcpy.da.SearchCursor(sourceFC, sourceFieldsList)} updateFC = r"C:\Path\UpdateFeatureClass" updateFieldsList = ["JoinField", "ValueField1", "ValueField2", "ValueField3", "ValueField4", "ValueField5"] with arcpy.da.UpdateCursor(updateFC, updateFieldsList) as updateRows: for updateRow in updateRows: # store the Join value of the row being updated in a keyValue variable keyValue = updateRow[0] # verify that the keyValue is in the Dictionary if keyValue in valueDict: # transfer the values stored under the keyValue from the dictionary to the updated fields. for n in range (1,len(sourceFieldsList)): updateRow[n] = valueDict[keyValue][n-1] updateRows.updateRow(updateRow) del valueDict print( "Finished script: " + strftime("%Y-%m-%d %H:%M:%S"))‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Example 3 - Transfer of Multiple Field Values between Feature Classes involving Complex Field Manipulations   If you need to do more complex field transfers that do more than a simple transfer of data from one table to another you can do this using code similar to the example field calculations that were done on a single table.  Here are the 3 field updates of my second field calculation example done between two separate tables with common join values instead of all within a single table.   from time import strftime print( "Start script: " + strftime("%Y-%m-%d %H:%M:%S")) import arcpy sourceFC = r"C:\Path\SourceFeatureClass" sourceFieldsList = ["JoinField", "ValueField", "NumberField1", "NumberField2", "CapitalizedField" ] # Use list comprehension to build a dictionary from a da SearchCursor valueDict = {r[0]:(r[1:]) for r in arcpy.da.SearchCursor(sourceFC, sourceFieldsList)} updateFC = r"C:\Path\UpdateFeatureClass" updateFieldsList = ["JoinField", "UrlField1", "SumField", "TitleCaseField"] with arcpy.da.UpdateCursor(updateFC, updateFieldsList) as updateRows: for updateRow in updateRows: keyValue = updateRow[0] # verify that the keyValue is in the Dictionary if keyValue in valueDict: # updateRow[1] is the URL field and valueDict[keyValue][0] is the value field updateRow[1] = r" http://pic.asrclkrec.com/view_ParcelMaps.aspx?ParcelNumber= " + str(valueDict[keyValue][0]) # updateRow[2] is the Sumfield and valueDict[keyValue][1] and valueDict[keyValue][2] are the NumberField1 and NumberField2 fields. updateRow[2] = valueDict[keyValue][1] + valueDict[keyValue][2] # updateRow[3] is the TitleCaseField and valueDict[keyValue][3] is the CapitalizedField values. updateRow[3 ] = valueDict[keyValue][3 ].title() updateRows.updateRow(updateRow) del valueDict print( "Finished script: " + strftime("%Y-%m-%d %H:%M:%S")) ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Creating a Multi-Field Python Dictionary Key to Replace a Concatenated Join Field:   Handling Multi-field join values that match records between two feature classes is also possible using dictionaries and cursors without having to do concatenation of separate fields into a new field.  The concatenation is still necessary, but it can be handled on the fly in memory, which is much faster than calculating a field.  Below shows an example of the single field transfer, but this time matching records using 3 separate fields to define the unique values between the feature classes used to match the records between the feature classes.   from time import strftime print( "Start script: " + strftime("%Y-%m-%d %H:%M:%S")) import arcpy sourceFC = r"C:\Path\SourceFeatureClass" sourceFieldsList = ["JoinField1", "JoinField2", "JoinField3", "ValueField"] # Use list comprehension to build a dictionary from a da SearchCursor where the key values are based on 3 separate feilds valueDict = {str(r[0]) + "," + str(r[1]) + "," + str(r[2]):(r[3:]) for r in arcpy.da.SearchCursor(sourceFC, sourceFieldsList)} updateFC = r"C:\Path\UpdateFeatureClass" updateFieldsList = ["JoinField1", "JoinField2", "JoinField3", "ValueField"] with arcpy.da.UpdateCursor(updateFC, updateFieldsList) as updateRows: for updateRow in updateRows: # store the Join value by combining 3 field values of the row being updated in a keyValue variable keyValue = updateRow[0]+ "," + str(updateRow[1]) + "," + str(updateRow[2] # verify that the keyValue is in the Dictionary if keyValue in valueDict: # transfer the value stored under the keyValue from the dictionary to the updated field. updateRow[3] = valueDict[keyValue][0] updateRows.updateRow(updateRow) del valueDict print( "Finished script: " + strftime("%Y-%m-%d %H:%M:%S")) ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Replacing Successive Joins with Simultaneous Processing of Several Python Dictionaries Built using da SearchCursors   When several joins have to be created and removed to do data manipulation between tables, the speed gains can be increased even more, since you can create several dictionaries and then process all of the join relationships simultaneously during a single pass of the update cursor on the updated feature class.  All source tables should be read into dictionaries before  processing the update cursor to achieve this benefit.  The more joins that you can replace this way, the more your script speed will improve.   Below is an example where two feature classes that would normally be joined to the updated feature class are replaced by dictionaries and the processed simultaneously by a single UpdateCursor operation.   from time import strftime print( "Start script: " + strftime("%Y-%m-%d %H:%M:%S")) import arcpy sourceFC = r"C:\Path\SourceFeatureClass1" sourceFieldsList = ["JoinField1", "ValueField", "NumberField1", "NumberField2" ] # Use list comprehension to build a dictionary from a da SearchCursor valueDict1 = {r[0]:(r[1:]) for r in arcpy.da.SearchCursor(sourceFC, sourceFieldsList)} sourceFC = r"C:\Path\SourceFeatureClass2" sourceFieldsList = ["JoinField2", "CapitalizedField" ] # Use list comprehension to build a dictionary from a da SearchCursor valueDict2 = {r[0]:(r[1:]) for r in arcpy.da.SearchCursor(sourceFC, sourceFieldsList)} updateFC = r"C:\Path\UpdateFeatureClass" updateFieldsList = ["JoinField1", "UrlField1", "SumField", "JoinField2", "TitleCaseField"] with arcpy.da.UpdateCursor(updateFC, updateFieldsList) as updateRows: for updateRow in updateRows: keyValue1 = updateRow[0] # verify that the keyValue1 is in the First Dictionary if keyValue1 in valueDict1: # updateRow[1] is the URL field and valueDict1[keyValue1][0] is the value field updateRow[1] = r" http://pic.asrclkrec.com/view_ParcelMaps.aspx?ParcelNumber= " + str(valueDict1[keyValue1][0]) # updateRow[2] is the Sumfield and valueDict1[keyValue1][1] and valueDict1[keyValue1][2] are the NumberField1 and NumberField2 fields. updateRow[2] = valueDict1[keyValue1][1] + valueDict1[keyValue1][2] keyValue2 = updateRow[3] # verify that the keyValue2 is in the Second Dictionary if keyValue2 in valueDict2: # updateRow[4] is the TitleCaseField and valueDict2[keyValue2][0] is the CapitalizedField values. updateRow[4 ] = valueDict2[keyValue2 ][0].title() updateRows.updateRow(updateRow) del valueDict1 del valueDict2 print( "Finished script: " + strftime("%Y-%m-%d %H:%M:%S")) ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Using a Python Dictionary Built using a da SearchCursor to Replace a Summary Statistics Output Table   Another common need is to create a summary of a feature class for the unique values of a field or fields that cover multiple records.  The Python Dictionary can be used instead of a Summary Table output to accomplish this.  The benefit is that the output is stored in memory and is much faster to create than outputting an actual summary table.  Below is an example building a summary dictionary and using it to update the source table with sum values matching that field and create a percentage field in the source table for each record that built the summary.   from time import strftime print( "Start script: " + strftime("%Y-%m-%d %H:%M:%S")) import arcpy sourceFC = r"C:\Path\UpdateFeatureClass" sourceFieldsList = ["UniqueValuesField", "NumberField"] # Build a summary dictionary from a da SearchCursor with unique key values of a field storing a list of the sum of that value and the record count. valueDict = {} with arcpy.da.SearchCursor(sourceFC, sourceFieldsList) as searchRows: for searchRow in searchRows: keyValue = searchRow[0] if not keyValue in valueDict: # assign a new keyValue entry to the dictionary storing a list of the first NumberField value and 1 for the first record counter value valueDict[keyValue] = [searchRow[1], 1] # Sum the last summary of NumberField value with the current record and increment the record count when keyvalue is already in the dictionary else: valueDict[keyValue][0] += searchRow[1] valueDict[keyValue][1] += 1 updateFC = r"C:\Path\UpdateFeatureClass" updateFieldsList = ["UniqueValuesField", "NumberField", "PercentField", "NumberSumField", "MeanField"] with arcpy.da.UpdateCursor(updateFC, updateFieldsList) as updateRows: for updateRow in updateRows: # store the Join value of the row being updated in a keyValue variable keyValue = updateRow[0] # verify that the keyValue is in the Dictionary if keyValue in valueDict: # divide the current record's NumberField value by the sum of the NumberField to get a percentage value updateRow[2] = updateRow[1] / valueDict[keyValue][0] # transfer the sum of the NumberField stored under the keyValue from the dictionary. updateRow[3] = valueDict[keyValue][0] # divide the sum of the NumberField value by the record count of the NumberField to get a mean value updateRow[4] = valueDict[keyValue][0] / valueDict[keyValue][1] updateRows.updateRow(updateRow) del valueDict print( "Finished script: " + strftime("%Y-%m-%d %H:%M:%S")) ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍   Conclusion   Once the patterns are understood it is possible to do virtually everything that you can do with the Field Calculator, a Join or a Summary table using an update cursor or a python dictionary.   Using these coding techniques I have been able to rewrite several scripts that did bulk Data Manipulations so that rather than taking more than an hour each to process, they now only take 3 to 10 minutes to process.  The more of these operations that you can replace using code like this, the greater the savings in processing time you will achieve.  The performance gains can be huge making it possible to keep data up to date without extensive waits or consuming large portions of your after hours batch processing time.  It also solves the problems that arise when you cannot alter the source data schema to add indexes or field concatenations and making copies of the data is not practical.   if you find any errors in the sample code, please let me know and I will post an update to this Blog to point out the correction. Also if you need more comments added to the code to help you understand what is going on, let me know and I will try to comment the code more fully.  These code examples are designed to work on shapefiles, file geodatabase feature classes, and unversioned SDE feature classes.  Additional code modifications are required to make them work with versioned SDE feature classes.   I want to express my thanks to Chris Synder who first demonstrated the usefulness of these techniques to me through the Forum and helped me understand how to apply them. ... View more