Why is UpdateCursor not updating the attributes of my shapefile?

Question

I am calculating buffer widths based on the ages of polygons. The buffer widths are stored in a new column in the attribute table. The code is:

with arcpy.da.UpdateCursor(hf,["FEATURE","YEAR","BUff"]) as cursor:
for row in cursor:
    f_type = row[0]
    year = row[1]
    buff = row[2]
    if f_type == "GRASSLAND":
        age = 2012 - int(year)
        if age > 60:
            buff = 0
            cursor.updateRow(row)
        if age <=60:
            buff = (10 * age) / 50
            cursor.updateRow(row)

Why is this code not successfully editing the attribute table?

Answer 1

The reason this code runs, but fails to update the attribute table, is due to my use of variables to represent the called attribute values. I attempted to make the code more legible by substituting variables for row[0], row[1], and row[2]. As a result, when I "updated" the values of the Buff attribute using buff = (10 * age) / 50, I was only updating the value of the variable, not the attribute table. Here is the corrected, functional code:

with arcpy.da.UpdateCursor(hf,["FEATURE","YEAR","BUff"]) as cursor:
for row in cursor:
    f_type = row[0]
    year = row[1]
    if f_type == "GRASSLAND":
        age = 2012 - int(year)
        if age > 60:
            row[2] = 0
            cursor.updateRow(row)
        if age <=60:
            row[2] = (10 * age) / 50
            cursor.updateRow(row)