Loop through multiple folder and Calculate mean of raster of Same folder

[ShouvikJha]

Hi All, 

I am writing a script to loop through multiple folders and calculate mean of the raster of each folder's data sets and save it in same folder. Below script i am working, but its not producing the mean rasters for each year folder, after running the script its generating only name of "mean" raster in main folder, and overlapping it .

Below images showing the name of the raster in one folder, another folder the raster name is same, only year value is changed in different year.
here how to take the year value in name of mean raster (E.g. for 2001 folder, output mean raster name would be Mean_Temp_2001.tif, E.g. for 2002 folder, output mean raster name would be Mean_Temp_2002.tif)

Below i have attached data sets also (Test_data folder)v which i am working on. 

Thanks. 

import arcpy, os
from arcpy import env
arcpy.CheckOutExtension("Spatial") 
arcpy.env.overwriteOutput = True
env.workspace = r"D:\Test"
outraster = env.workspace


walk = arcpy.da.Walk(env.workspace, topdown=True, datatype="RasterDataset")
for dirpath, dirnames, filenames in walk:
    print dirpath
    rasterList = []
    for file in filenames:
        raster = os.path.join(dirpath, file)
        rasterList.append(raster)
        rasMean = arcpy.sa.CellStatistics(rasterList,"MEAN")
        rasMean.save(os.path.join(outraster,"mean.tif"))
        print rasMean‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

[IanMurray]

If you are running this as a standalone script, you will need to have arcpy check out a Spatial Analyst Extension.

[ShouvikJha]

i added the line,but its behave the same as earlier . 

arcpy.CheckOutExtension("Spatial") ‍

[ShouvikJha]

@lan , i heve updated  above code, but its producing only single output name "mean" and overlapping the output for multiple time in main folder, output not save in source of input raster folder  

[NeilAyres]

Take this out of the loop.

rasMean = arcpy.sa.CellStatistics(rasterList,"MEAN")
rasMean.save(os.path.join(outraster,"mean.tif"))
print rasMean‍‍‍

Assemble the rasterList first, then calculate the mean

[ShouvikJha]

Thank you, May i get one example of this 

[DanPatterson_Retired]

Neil is suggesting dedenting the last 3 lines so that cell statistics is performed on the whole list rather incrementally as your script is doing.  Note, all the folders must be within one folder or a subfolder within it

[ShouvikJha]

Hi, I have updated my script, Below script printing only folder name, its not calculating the mean of raster from different folder 

Script: 

import arcpy, os
from arcpy import env
arcpy.CheckOutExtension("Spatial")
arcpy.env.overwriteOutput = True
env.workspace = r"D:\Test"
outraster = env.workspace


walk = arcpy.da.Walk(env.workspace, topdown=True, datatype="RasterDataset")
for dirpath, dirnames, filenames in walk:
    print dirpath
    rasterList = []
    for file in filenames:
        raster = os.path.join(dirpath, file)
        rasterList = arcpy.ListRasters("TIF")
    for Rasters in rasterList:
        rasMean = arcpy.sa.CellStatistics(Rasters,"MEAN", "DATA")
        file_name_only = os.path.splitext(Rasters)[0]
        tifname = file_name_only[-4:]
        rasMean.save(os.path.join(outraster,'Mean_{0}.tif'.format(tifname)))
        print rasMean‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

After running the script, its printing folder only 

D:\Test
D:\Test\2001
D:\Test\2002
D:\Test\2003
D:\Test\2004
D:\Test\2005
D:\Test\2006
D:\Test\2007
D:\Test\2008
D:\Test\2009‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

[DanPatterson_Retired]

You do realize that rasmean is a raster and not a single number don't you?  And don't you want lines 16-21 indented one more level?

[ShouvikJha]

Patterson i have updated the line 16-19, still script behave the same 

for Rasters in rasterList:
        rasMean = arcpy.sa.CellStatistics(Rasters,"MEAN", "DATA")
        file_name_only = os.path.splitext(Rasters)[0]
        tifname = file_name_only[-4:]‍‍‍‍