Compare fields for matches

[TonyAlmeida]

I need to compare fields from two separate tables and mark them with copy or no copy. It seems easy enough but i am having a hard time and not sure what I am doing wrong. I just get all "No" in the Copy field.

Here is what i have.

fc1 = 'C:\Temp\blah1.dbf' 
fc2 = 'C:\Temp\blah2.dbf'

cursor1 = arcpy.da.SearchCursor(fc1, ["Field1", "Copy"])  
cursor2 = arcpy.da.SearchCursor(fc2, ["Field2"])

with arcpy.da.UpdateCursor(fc1, ['Field1', 'Copy']) as cursor:
    for row in cursor1:
        for row2 in cursor2: 
            if row[0].strip().lower()!= row[0].strip().lower(): 
                for row1 in cursor1:
                    row[1] = 'No'
                else:
                    row[1] = 'Copy'
                cursor.updateRow(row1)
del cursor‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

[DavidPike]

I'm not sure your list comprehension is working in your cursor. Check your list is being populated  if not, replace with a noob append on fclist.

[TonyAlmeida]

This list is working i add a print statement for the list. Not sure what part my code is failing.

fc1 = 'C:\Temp\blah1.dbf' 
fc2 = 'C:\Temp\blah2.dbf'

fc1List = []

with arcpy.da.SearchCursor(fc2,["Field2"]) as cursor:
    fc1List = [row for row in cursor]
print (fc1List)

tableFieldList = ["Field1", "Copy"]

with arcpy.da.UpdateCursor(fc1, tableFieldList) as tablecursor:
    for tablerow in tablecursor:
        if tablerow[0] in fc1List:
            tablerow[1] = 'Copy'
        else:
            tablerow[1] = 'No'
        tablecursor.updateRow(tablerow)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

[DavidPike]

Looking at the code it seems absolutely fine. Is the comparison messing up on different data types, e.g.  string and float?

[DanPatterson_Retired]

Ran a test on my own data, could be what it is returning.

# ---- this returns tuples of values
with arcpy.da.SearchCursor(tbl1,["Text_vals"]) as cursor:
    fc1List = [row for row in cursor]
    
fc1List
[('zilch',)]

# ---- This returns values
with arcpy.da.SearchCursor(tbl1,["Text_vals"]) as cursor:
    fc1List = [row[0] for row in cursor]
    

fc1List
['zilch']‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

So you can't compare single values to tuples in case that is what you are getting.

Try seeing if the checks work before you go to the updatecursor

# tbl1, tbl2 are two tables with a common field (Text_vals)

with arcpy.da.SearchCursor(tbl1, ["Text_vals"]) as cursor:
    fc1List = [row[0] for row in cursor]
print (fc1List)

tableFieldList = ['Text_vals']  # ---- field to check
with arcpy.da.SearchCursor(tbl2, tableFieldList) as tablecursor:
    for tablerow in tablecursor:
        if tablerow[0] in fc1List:
            print("is in")
        else:
            print("not in")

# ---- print and run results           
['zilch'.....

is in
....‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

[RandyBurton · Accepted solution]

Does something like this help:

fc1 = "C:\Temp\blah1.dbf"
fld1 = ["Field1", "Copy"]


fc2 = "C:\Temp\blah2.dbf"
fld2 = ["Field2"]


valueList = [r[0] for r in arcpy.da.SearchCursor(fc2, fld2)]


with arcpy.da.UpdateCursor(fc1, fld1) as cursor:
    for row in cursor:
        if row[0] in valueList:
            row[1] = 'Copy'  # May wish to swap 'Copy' and 'No'
        else:
            row[1] = 'No'
        cursor.updateRow(row)‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

[DanPatterson_Retired]

exactly my point..that is the slice that is needed. (my example, your example

fc1List = [row[0] for row in cursor]

valueList = [r[0] for r in arcpy.da.SearchCursor(fc2, fld2)]

If tuples are being returned, then it has to be sliced

'zilch' in [('zilch',)]
Out[1]: False
'zilch' in [('zilch',)[0]]
Out[2]: True
'zilch' in ['zilch']
Out[3]: True‍‍‍‍‍‍