Edit attribute table for shapefiles in folders and subfolders with arcpy?

Question

Continuously to Merge shapefiles in folders and subfolders with arcpy I try to edit attribute table for 20 shapefiles that spread in big a folder and are divided to a lot of sub folders. All shapefiles are called "migrashim" and the name of the filed that i want to change is "structuretype". I try this code:

import arcpy,os,sys,string,fnmatch,arcpy.mapping
from arcpy import env

rootPath = r"C:\Project\layers"
pattern = 'migrashim.shp'
features = arcpy.UpdateCursor(r"C:\Project\layers\*.shp")
counter = 0
for root, dirs, files in os.walk(rootPath):
    for filename in files:
        if filename == "migrashim.shp":
            for feature in features:
                if feature.structuretype == 3:
                feature.structuretype = 4
                features.updateRow(feature)
        counter = counter + 1
print 'edit'
print counter
del feature,features

but i got an error:

IOError: "C:\Project\layers\migrashim.shp" does not exist

What wrong with my code?

Answer 1

I would use below code--

If you have access to "Data Access Module"

import arcpy,os,sys
pattern = 'fish_46.shp'
folder = 'C:\Users\USER_NAME\Desktop\delete'## root folder
field = 'Id' ## your field where calculation to be applied
files_process = []
for root,dirs,files in os.walk('C:\Users\USER_NAME\Desktop\delete'):
    for filenames in files:
        if filenames == pattern:
            files_process.append(os.path.join(root, filenames))

for i in files_process:
    curU = arcpy.da.UpdateCursor(i,field)
    for row in curU:
        row[0]=1 ##Any expression you want
        curU.updateRow(row)
del curU

EDIT

If you do not have access to "Data Access Module"

import arcpy,os,sys
pattern = 'fish_46.shp'
folder = 'C:\Users\USER_NAME\Desktop\delete'## root folder
field = 'Id' ## your field where calculation to be applied
files_process = []
for root,dirs,files in os.walk('C:\Users\USER_NAME\Desktop\delete'):
    for filenames in files:
        if filenames == pattern:
            files_process.append(os.path.join(root, filenames))

for i in files_process:
    curU = arcpy.UpdateCursor(i)
    for row in curU:
        row.setValue(field, 500)##Any expression you want
        curU.updateRow(row)
del curU