qgis - How to find and replace attribute values based on a list

I have a Shapefile and a list in .csv which contains two columns with names:

• "Old_name" which contains the old names that already exist in the attribute table of the previously mentioned Shapefile; and


• "New_name" which contains the updated name.

How can I do this either on ArcGIS, QGIS or with python?

Based on this question I need to use the UpdateCursor function, but how can I use the list in this function?

Answer

Assuming the csv is ready to be consumed by arcpy as a table with two columns named OLD_NAME and NEW_NAME, and following the example provided in the question to get to the source shp in the UpdateCursor.

#create a dictionary of the csv to join to the shapefile
#r[0] is the first item passed to the SearchCursor and used to join to shp
#r[1] is the second item and used for the update

csvDict= dict([(r[0], (r[1])) for r in arcpy.da.SearchCursor(my_csv, ["OLD_NAME","NEW_NAME"])]) 

with arcpy.da.UpdateCursor(my_shp, ["OLD_NAME","NEW_NAME"]) as cursor:
    for row in cursor:
        joinFieldValue = row[0] #this is "OLD_NAME" on the shapefile            
        if row[0]  in csvDict: #check to see if old_name exists in new 
            row[1] = csvDict[joinFieldValue]
        else:
            row[1] = row[0] #new name is same as the old name
        cursor.updateRow(row)

    del cursor, row