Update Cursor Script Not Running

Question

I have a script I want to use to update a value for a group of selected features in ArcMap in a string field. I am using the UpdateCursor method but I cannot get the output generated that I want. I know my code is close but something is off. Here is my code:

import arcpy
fc = r'D:\_data\sidewalk.gdb\repairs'
cursor = arcpy.UpdateCursor(fc)
for row in cursor:
 if row.FixedBy == '':
 row.FixedBy = 'Contractor'
 cursor.updateRow(row)
print "Processing complete"
del row

I am trying to update the string "FixedBy" field where values are blank, not 'Null', with the value 'Contractor'. What is my code missing?

• Aaron: cursor.updateRow(row) should be unindented. Try replacing row.FixedBy == '' with row.FixedBy == None. Also, I would recommend using the new data access da cursors.
• cbunn: I get a syntax error when i unindent curcor.updateRow(row). Any my originaly value is not Null but rather blank.
• Aaron: Try adding a print statement within your cursor to see what the true value is of your row.
• cbunn: Would you mind providing a full answer, then I can mark it as correct if it runs.
• Bjorn: Using CalculateField_management might be an easier approach

Answer 1

This should work if the value of FixedBy is NULL or blank (meaning no text at all, including spaces):

import arcpy
fc = r'D:\_data\sidewalk.gdb\repairs'
with arcpy.da.UpdateCursor(fc,['FixedBy']) as cursor:
 for row in cursor:
 if row[0] == None or row[0] == '':
 row[0] = 'Contractor'
 cursor.updateRow(row)

• cbunn: This runs perfectly thank you! If the GDB is stored on an SDE server what would the file path look like?
• umbe1987: Glad it helped. You could look at this answer to know how to do that. gis.stackexchange.com/a/5541/9518.

Answer 2

One idea is to pass in a where clause to the UpdateCursor; then you don't need to check any values. All rows returned could be updated.

Assuming you are using 10.1+, switching to arcpy.da cursors is also recommended.

import arcpy
fc = r'D:\_data\sidewalk.gdb\repairs'
i = 0
with arcpy.da.UpdateCursor(fc, ['FixedBy'], "FixedBy =''") as cursor:
 for row in cursor:
 row[0] = 'Contractor'
 cursor.updateRow(row)
 i += 1
print "Processed {}...".format(i)

(Untested code.)

If the count is 0, there is a problem with your where clause or your data isn't what you think you are seeing.

• Bjorn: OP mentioned in the comments that other edits were also being made in the cursor loop, so the where clause may not be appropriate in this specific case.
• cbunn: It says it processed all the records despite me only selecting 2 records for it to run against. Also it did not update the "FixedBy" field. It is a string field in a File GDB. How do I adjust my where clause?
• Bjorn: @cbunn Try "\"FixedBy\" = ''" as your where clause