How to use the local macro to do ZonalStatisticsAsTable in batch

Question

I have a series of files named as 'rawfile200101', 'rawfiles200102',...,'rawfile201104'. I want to do ZonalStatisticsAsTable for each of them with names corresponding to the time of the raw files, such as 'newfile200101', 'newfiles200102',...,'newfile201104'. I know how to script it for individal file, but I am trying to do it in batch. I wrote the following codes for four files, it is always shown error that "I:/rawfile%list%.tif" does not exist.

import arcpy
from arcpy import env
from arcpy.sa import *
arcpy.CheckOutExtension("Spatial")

yrmn = ['200101', '200102', '200103', '200104']

for list in yrmn:
    outZSaT = ZonalStatisticsAsTable("I:/boundaries", "ID", "I:/rawfile%list%.tif", "I:/newfile%list%.dbf", "DATA", "SUM")

Answer 1

Python won't substitute variables like %list% into strings like how ModelBuilder does. Here's the most basic way to do it in Python using string concatenation:

import arcpy
from arcpy import env
from arcpy.sa import *
arcpy.CheckOutExtension("Spatial")

yrmn = ['200101', '200102', '200103', '200104']

for list in yrmn:
    in_value_raster = "I:/rawfile" + list + ".tif"
    out_table = "I:/newfile" + list + ".dbf"
    outZSaT = ZonalStatisticsAsTable("I:/boundaries", "ID", in_value_raster, out_table, "DATA", "SUM")

You could also use string formatting operations:

    in_value_raster = "I:/rawfile%s.tif" % list
    out_table = "I:/newfile%s.dbf" % list

Python purists would prefer the str.format() method, since the above string formatted may be deprecated in Python 3.x:

    in_value_raster = "I:/rawfile{}.tif".format(list)
    out_table = "I:/newfile{}.dbf".format(list)