Using cursor to make all LONG fields with NULL values 0 in ArcPy?

Question

I have a table that I am joining to calculate several long integer fields, when the join is executed all of the values are joined as NULL that don't have values.

How can I use an Update Cursor to calculate every NULL value to 0 that is in a field that has a long integer type?

How can I expand upon this example to iterate through each field that is not a string(double, long) and change all NULL values to 0?

This only needs to be done to one field; however the script below does not update my NULL values to 0.

import arcpy

distfc = 'aFC'

with arcpy.da.UpdateCursor(distfc, ["FREQUENCY"]) as cursor:
    for row in cursor:
        if row[0] ==  NONE:
            row[0] = 0
            cursor.updateRow(row)

Answer 1

Python is case sensitive--therefore, you need to replace NONE with None (a reserved word in Python)

import arcpy

distfc = 'aFC'

with arcpy.da.UpdateCursor(distfc, ["FREQUENCY"]) as cursor:
    for row in cursor:
        if row[0] ==  None:
            row[0] = 0
            cursor.updateRow(row)