Joining .csv to attribute table in ArcMap?

Question

enter image description hereIs there an ArcMap 10.5 method of joining an excel file (.csv) to a shapefile/attribute table using several fields instead of an explicit identifier?

I've been having trouble with this, and joins simply appends it and fills all rows in the attribute table with the first row from excel.

They don't share a specific number ID, but both have columns (fields?) such as "Township", "Lot", and "Concession" that share the same data. I am looking to join it using these as identifiers and then fill the remaining columns with the excel data.

In summary, is there a way to simply fill the fields in the attribute table with the data from excel?

• Ben S Nadler: The short answer is no. The long answer is "concatenate"
• Bera: Add a field to the attribute table and calculate it as Township+Lot+Concession, do the same in the csv and then join on this field.
• Paul: @BERA it worked, thank you! Do you know of a fast way to join those in Arc though? So far I've been going through and manually inputting "Township+Concession+Lot".
• Bera: Nice! By manually you med typing it in for each field? If so dont do that, use Field Calculator. You could also use Python. Could you add a screenshot of the attribute table and the csv file?
• Paul: @BERA I added the images above. The .csv became a mess though, for some reason. I have yet to learn python though, and the shapefile does not appear in the field calculator, I assume this is because it's simply a polygon file (broken down into lots).

Answer 1

Add a field to the attribute table and calculate it as Township+Lot+Concession using Field Calculator, do the same in the csv and then join on this field.

Or if you want to complicate things you can also use some Python code. I create a dictionary from the csv file and use this to update fields in the attribute table. You will need to adjust the indexing to match the columns in the csv file, see comment below:

import arcpy
csvfile = r'C:\Test\csvfile.csv' #Change to match your data
fc = r'C:\filegeodatabase.gdb\feature_class' #Change to match your data
d = {} #Create empty dictionary
#Read the lines of the csvfile and and to dictionary
with open(csvfile,'r') as f:
 f.readline() # skip header line
 for line in f:
 row=line.split(',') #Change , to what delimits the fields
 #You might need to adjust indexing on the following row to match the columns of the csv file:
 d[row[0]+row[1]+row[2]]=[row[3],row[4],row[5]]
with arcpy.da.UpdateCursor(fc,['TOWNSHIP','CONCESSION','LOT','LAST_NAME','FIRST_NAME','PPA']) as cursor:
 for row in cursor:
 try:
 row[3],row[4],row[5]=d[row[0]+row[1]+row[2]]
 cursor.updateRow(row)
 except:
 print '{0} {1} {2} was not found in the csvfile'.format(*list(row[3],row[4],row[5]))

Example of indexing: enter image description here

• Paul: Thank you so much for taking the time to do all of this! It has really helped me.