[GIS] Using Update Cursor to update all fields in a feature class based upon another feature class

arcgis-10.3arcpycursorfeature-class

I have perused GIS stack exchange to find an answer, but haven't quite found what I am looking for.

Question: How can I update all the fields in a feature class based upon field values from another feature class?

Here is my original feature class, (image on left) with 896 records of which I only need to update 11 records from the old feature class with the 11 records shown in the new UpdatedTAZnumbers feature class (image on right).

The new feature class which has the correct updated values has the exact same fields just with different values in them. There are over 100 fields thus joining the layers and using field calculator would take forever.

Therefore, I am thinking a script and in this case perhaps an updatecursor would be the best route to take.

I am fairly new to python and am struggling with something that seems so simple.
My script below currently does not work and I know it starts with the line in the update cursor

 *while row:
 row.setValue(oldfc, row.getValue(newfc))*

I am using ArcGIS 10.3.1 and Python 2.7.

    import arcpy
    from arcpy import env

    from datetime import datetime
    startTime = datetime.now()

    arcpy.env.workspace = r"workspace.gdb"


    oldfc = r"workspace.gdb\TAZfromTransCAD...."

    newfc = r"workspace.gdb\UpdatedTAZnumbers"


    ##
    ##oldfields = [u'OBJECTID', u'Shape', u'ID', u'AREA', u'AREA1', u'TAZ', u'ACRES', u'HH2005', u'HH2010', u'HH2015', u'HH2020', u'HH2025', u'HH2030', u'HH2035', u'LOWINCHH05', u'LOWINCHH10', u'LOWINCHH15', u'LOWINCHH20', u'LOWINCHH25', u'LOWINCHH30', u'LOWINCHH35', u'MEDINCHH05', u'MEDINCHH10', u'MEDINCHH15', u'MEDINCHH20', u'MEDINCHH25', u'MEDINCHH30', u'MEDINCHH35', u'HIINCHH05', u'HIINCHH10', u'HIINCHH15', u'HIINCHH20', u'HIINCHH25', u'HIINCHH30', u'HIINCHH35', u'HHPOP2005', u'HHPOP2010', u'HHPOP2015', u'HHPOP2020', u'HHPOP2025', u'HHPOP2030', u'HHPOP2035', u'GQPOP2005', u'GQPOP2010', u'GQPOP2015', u'GQPOP2020', u'GQPOP2025', u'GQPOP2030', u'GQPOP2035', u'HHOF1_2005', u'HHOF1_2010', u'HHOF1_2015', u'HHOF1_2020', u'HHOF1_2025', u'HHOF1_2030', u'HHOF1_2035', u'HHOF2_2005', u'HHOF2_2010', u'HHOF2_2015', u'HHOF2_2020', u'HHOF2_2025', u'HHOF2_2030', u'HHOF2_2035', u'HHOF3_2005', u'HHOF3_2010', u'HHOF3_2015', u'HHOF3_2020', u'HHOF3_2025', u'HHOF3_2030', u'HHOF3_2035', u'HHOF4_2005', u'HHOF4_2010', u'HHOF4_2015', u'HHOF4_2020', u'HHOF4_2025', u'HHOF4_2030', u'HHOF4_2035', u'HHOF5_2005', u'HHOF5_2010', u'HHOF5_2015', u'HHOF5_2020', u'HHOF5_2025', u'HHOF5_2030', u'HHOF5_2035', u'HHOF6_2005', u'HHOF6_2010', u'HHOF6_2015', u'HHOF6_2020', u'HHOF6_2025', u'HHOF6_2030', u'HHOF6_2035', u'HHOF7_2005', u'HHOF7_2010', u'HHOF7_2015', u'HHOF7_2020', u'HHOF7_2025', u'HHOF7_2030', u'HHOF7_2035', u'POP019_05', u'POP019_10', u'POP019_15', u'POP019_20', u'POP019_25', u'POP019_30', u'POP019_35', u'POP2054_05', u'POP2054_10', u'POP2054_15', u'POP2054_20', u'POP2054_25', u'POP2054_30', u'POP2054_35', u'POP55_05', u'POP55_10', u'POP55_15', u'POP55_20', u'POP55_25', u'POP55_30', u'POP55_35', u'ELEM2005', u'ELEM2010', u'ELEM2015', u'ELEM2020', u'ELEM2025', u'ELEM2030', u'ELEM2035', u'HISCHL2005', u'HISCHL2010', u'HISCHL2015', u'HISCHL2020', u'HISCHL2025', u'HISCHL2030', u'HISCHL2035', u'COLLEGE05', u'COLLEGE10', u'COLLEGE15', u'COLLEGE20', u'COLLEGE25', u'COLLEGE30', u'COLLEGE35', u'AMC2005', u'AMC2010', u'AMC2015', u'AMC2020', u'AMC2025', u'AMC2030', u'AMC2035', u'MTCUW2005', u'MTCUW2010', u'MTCUW2015', u'MTCUW2020', u'MTCUW2025', u'MTCUW2030', u'MTCUW2035', u'RETAIL2005', u'RETAIL2010', u'RETAIL2015', u'RETAIL2020', u'RETAIL2025', u'RETAIL2030', u'RETAIL2035', u'SVCOFC2005', u'SVCOFC2010', u'SVCOFC2015', u'SVCOFC2020', u'SVCOFC2025', u'SVCOFC2030', u'SVCOFC2035', u'OTHER2005', u'OTHER2010', u'OTHER2015', u'OTHER2020', u'OTHER2025', u'OTHER2030', u'OTHER2035', u'GAMING2005', u'GAMING2010', u'GAMING2015', u'GAMING2020', u'GAMING2025', u'GAMING2030', u'GAMING2035', u'HOTELRM05', u'HOTELRM10', u'HOTELRM15', u'HOTELRM20', u'HOTELRM25', u'HOTELRM30', u'HOTELRM35', u'PARKING05', u'PARKING10', u'PARKING15', u'PARKING20', u'PARKING25', u'PARKING30', u'PARKING35', u'JURISDICT', u'JURISDNUM', u'REGCTR_TOD', u'RC_TOD_NUM', u'DISTRICT57', u'SHAPE_LENG', u'CBD', u'DISTRICT20', u'DISTNAME20', u'SHAPE@']
    ##newfields = [u'OBJECTID', u'Shape', u'ID', u'AREA',u'AREA1', u'TAZ', u'ACRES', u'HH2005', u'HH2010', u'HH2015', u'HH2020', u'HH2025', u'HH2030', u'HH2035', u'LOWINCHH05', u'LOWINCHH10', u'LOWINCHH15', u'LOWINCHH20', u'LOWINCHH25', u'LOWINCHH30', u'LOWINCHH35', u'MEDINCHH05', u'MEDINCHH10', u'MEDINCHH15', u'MEDINCHH20', u'MEDINCHH25', u'MEDINCHH30', u'MEDINCHH35', u'HIINCHH05', u'HIINCHH10', u'HIINCHH15', u'HIINCHH20', u'HIINCHH25', u'HIINCHH30', u'HIINCHH35', u'HHPOP2005', u'HHPOP2010', u'HHPOP2015', u'HHPOP2020', u'HHPOP2025', u'HHPOP2030', u'HHPOP2035', u'GQPOP2005', u'GQPOP2010', u'GQPOP2015', u'GQPOP2020', u'GQPOP2025', u'GQPOP2030', u'GQPOP2035', u'HHOF1_2005', u'HHOF1_2010', u'HHOF1_2015', u'HHOF1_2020', u'HHOF1_2025', u'HHOF1_2030', u'HHOF1_2035', u'HHOF2_2005', u'HHOF2_2010', u'HHOF2_2015', u'HHOF2_2020', u'HHOF2_2025', u'HHOF2_2030', u'HHOF2_2035', u'HHOF3_2005', u'HHOF3_2010', u'HHOF3_2015', u'HHOF3_2020', u'HHOF3_2025', u'HHOF3_2030', u'HHOF3_2035', u'HHOF4_2005', u'HHOF4_2010', u'HHOF4_2015', u'HHOF4_2020', u'HHOF4_2025', u'HHOF4_2030', u'HHOF4_2035', u'HHOF5_2005', u'HHOF5_2010', u'HHOF5_2015', u'HHOF5_2020', u'HHOF5_2025', u'HHOF5_2030', u'HHOF5_2035', u'HHOF6_2005', u'HHOF6_2010', u'HHOF6_2015', u'HHOF6_2020', u'HHOF6_2025', u'HHOF6_2030', u'HHOF6_2035', u'HHOF7_2005', u'HHOF7_2010', u'HHOF7_2015', u'HHOF7_2020', u'HHOF7_2025', u'HHOF7_2030', u'HHOF7_2035', u'POP019_05', u'POP019_10', u'POP019_15', u'POP019_20', u'POP019_25', u'POP019_30', u'POP019_35', u'POP2054_05', u'POP2054_10', u'POP2054_15', u'POP2054_20', u'POP2054_25', u'POP2054_30', u'POP2054_35', u'POP55_05', u'POP55_10', u'POP55_15', u'POP55_20', u'POP55_25', u'POP55_30', u'POP55_35', u'ELEM2005', u'ELEM2010', u'ELEM2015', u'ELEM2020', u'ELEM2025', u'ELEM2030', u'ELEM2035', u'HISCHL2005', u'HISCHL2010', u'HISCHL2015', u'HISCHL2020', u'HISCHL2025', u'HISCHL2030', u'HISCHL2035', u'COLLEGE05', u'COLLEGE10', u'COLLEGE15', u'COLLEGE20', u'COLLEGE25', u'COLLEGE30', u'COLLEGE35', u'AMC2005', u'AMC2010', u'AMC2015', u'AMC2020', u'AMC2025', u'AMC2030', u'AMC2035', u'MTCUW2005', u'MTCUW2010', u'MTCUW2015', u'MTCUW2020', u'MTCUW2025', u'MTCUW2030', u'MTCUW2035', u'RETAIL2005', u'RETAIL2010', u'RETAIL2015', u'RETAIL2020', u'RETAIL2025', u'RETAIL2030', u'RETAIL2035', u'SVCOFC2005', u'SVCOFC2010', u'SVCOFC2015', u'SVCOFC2020', u'SVCOFC2025', u'SVCOFC2030', u'SVCOFC2035', u'OTHER2005', u'OTHER2010', u'OTHER2015', u'OTHER2020', u'OTHER2025', u'OTHER2030', u'OTHER2035', u'GAMING2005', u'GAMING2010', u'GAMING2015', u'GAMING2020', u'GAMING2025', u'GAMING2030', u'GAMING2035', u'HOTELRM05', u'HOTELRM10', u'HOTELRM15', u'HOTELRM20', u'HOTELRM25', u'HOTELRM30', u'HOTELRM35', u'PARKING05', u'PARKING10', u'PARKING15', u'PARKING20', u'PARKING25', u'PARKING30', u'PARKING35', u'JURISDICT', u'JURISDNUM', u'REGCTR_TOD', u'RC_TOD_NUM', u'DISTRICT57', u'SHAPE_LENG', u'CBD', u'DISTRICT20', u'DISTNAME20', u'SHAPE@']

    cursor = arcpy.UpdateCursor(fc)
    row =cursor.next()

    while row:
        row.setValue(oldfc, row.getValue(newfc))
        cursor.updateRow(row)
        row = cursor.next()


    print datetime.now() - startTime

Best Answer

To do this with ArcPy cursors I think you will need to use both a Search Cursor to read one table and an Update Cursor to write to the other.

Since you are using a version that is 10.1 or later I recommend using arcpy.da cursors rather than the old style because they are about 10 times as fast.

You would use a run through arcpy.da.SearchCursor() to load a Python dictionary with your IDs as the keys, and your values being a list of the field values.

Then use a run through arcpy.da.UpdateCursor() to read each list of field values and extract them into their correct fields.

However, if you did not have many fields to update and have a unique identifier that is common to both tables, then I think you will find this far easier to do in ArcMap (or ArcPy) by adding a join and then calculating fields in one table to be equal to joined fields from the other.

Related Solutions

[GIS] Updating Multiple Fields in Feature Class from a Table

First, let it be known there are a number of ways someone could go about accomplishing roughly the same goal in this case. For me personally, especially for someone less experienced with arcpy, it would likely be simplest to do roughly the following workflow

Convert the CSV file to Table in GDB
Join the Table to Point Feature Class
Make Feature Layer (geoprocessing tool, allows for selections to be applied)
Select by attribute against layer to select only those features that need updating (ex: select where JoinTable.OID IS NOT NULL)
Calculate field against the selected layer for each field needing updated.

By first making sure you have a selection applied, it shouldn't take too long to run through 70 or so records. I will admit, yes, it would be quicker and more efficient to use cursors to accomplish this, assuming you are at 10.1 or higher and have access to the arcpy.da cursors. But, for simplicity sake and ease of use, calculate field isn't a terrible option.

ArcPy – When to Update Row Within Update Cursor with Multiple If Statements

Run your cursor.updateRow(row) just once per row that includes any changes and run it after all changes for that row. Since you change values for every row (at least for the dates), then you need to run it once for each row, after all changes for the row.

Therefore run it as the last line in the for loop, outside of any if clauses. Ie, Use only one cursor.updateRow(row) statement.

The cursor.updateRow(row) writes all values for that row at once, so there's no point running it for each value. Run it once only for the entire row.

Eg:

with arcpy.da.UpdateCursor(ci_masterpoints, flds) as cursor:
    # start looking at rows
    for row in cursor:
        row[flds.index('TodaysDate')] = datetime.datetime.now().strftime('%d/%m/%Y')
        row[flds.index('TodaysDateYr')] = datetime.datetime.now().year
        age = row[flds.index('Age')]
        # If the work order number matches to a wonum in conditions...
        if mx_row in conditions:
            row[flds.index('Leak_Location')] = conditions[mx_row]
        # Avoid null values but assign year based on Actual_Finish
        if row[flds.index('Actual_Finish')] != None:
            # Assign the year to DateInstallYr
            row[flds.index('DateInstallYr')] = row[flds.index('Actual_Finish')].year
            age = row[flds.index('TodaysDateYr')] - row[flds.index('DateInstallYr')]
        if age == None:
            row[flds.index('AgeMult')] = 1
        elif age > 10 and age < 20:
             row[flds.index('AgeMult')] = 0.9
        elif age > 20:
            row[flds.index('AgeMult')] = 0.75
        cursor.updateRow(row)

Best Answer

Related Solutions

[GIS] Updating Multiple Fields in Feature Class from a Table

ArcPy – When to Update Row Within Update Cursor with Multiple If Statements

Related Question