topic Re: File saving and naming in Python Questions

File saving and naming

Leo_KrisPalao — Thu, 28 Aug 2014 09:41:24 GMT

Hi Python Users,

I want to automate my filenaming in my python script. This is what I am doing.

I am calculating a bunch of rasters using the implementation of raster calculator / map algebra in python. I want to save my output in this way:

PET_001.tif

PET_037.tif

here is the script that I am running:

clim = r'path\to\rasters'

arcpy.env.workspace = clim

clim_rasters = arcpy.ListRasters()

for raster in clim_rasters:

tmax_ras = arcpy.ListRasters("Tmax*")

tmin_ras = arcpy.ListRasters("Tmin*")

ra_ras = arcpy.ListRasters("RA*")

PET5 = 0.0023 * Raster(ra_ras) * ((Raster(tmax_ras) + Raster(tmin_ras) / 2.00) + 17.8) * ((Raster(tmax_ras) + Raster(tmin_ras))**0.5)

I need to save my output in such a way described above. Help please.

Thanks,

-Leo

Re: File saving and naming

AnthonyGiles — Thu, 28 Aug 2014 10:05:59 GMT

Have a look at the CreateUniqueName function:

ArcGIS Help 10.1

Re: File saving and naming

DanPatterson_Retired — Sat, 11 Dec 2021 17:44:11 GMT

or you could have some fun... then don't forget to save your raster

(ie Raster.save(outName)


'''
FileNamesPaddedZeros
padding filenames with zeros
'''


filename = "c:/temp/MyfileName.tif"
basename, extension = filename.split(".")

for i in range(40):
  padWith = "%03i." % 
  outName = basename + "/" + padWith + extension
  print outName

Re: File saving and naming

Leo_KrisPalao — Fri, 29 Aug 2014 09:33:28 GMT

Hi Dan and Anthony,

Thanks for your reply.

By the way Dan, I tried to copy your code and execute it. If my declared variable in filename is "PET_.tif", it only prints "PET_%03i.tif" and repeat it 40 times.

The padWith variable which is "%03i." % is throwing a syntax error. It is because of the last % character. If I remove the last % character it executes but print statement is like this:

PET_%03i.tif"

(40 times)

PET_%03i.tif"

Thanks for any help.

I am a just a python newbie and I am learning it through self study and of course through asking in the forum.

-Leo

Re: File saving and naming

DanPatterson_Retired — Fri, 29 Aug 2014 11:36:46 GMT

You have to give the whole path to the tiff's filename, not the variable name

Re: File saving and naming

curtvprice — Fri, 29 Aug 2014 17:13:48 GMT

I answered this for you on another post this morning

Run raster calculation on multiple lists of rasters

but I think we have another issue here - your code is assuming the ListRasters will only return one raster. Are you sure this is the case?

How are your data structured? Are these netCDF rasters that have rasters like "Tmax01" inside each raster?

Re: File saving and naming

Leo_KrisPalao — Thu, 11 Sep 2014 05:55:57 GMT

Hi Curtis and Dan,

Thanks for your suggestions.

By the way, Curtis, I changed the code and and followed the code in your other post. The files are numbered in sequence. Tmax_001, Tmax_002....Tmax_037

I think I have to read more about these strings and filenaming techniques in Python.

Thanks,

-Leo

Re: File saving and naming

curtvprice — Thu, 11 Sep 2014 15:40:26 GMT

The powerful string manipulation capabilities in Python are one of the things that make it so awesome.

These arcpy methods are very helpful with file naming as well, especially for temporary files: CreateScratchName, CreateUniqueName, ValidateTableName.

Re: File saving and naming

JeffWard — Thu, 11 Sep 2014 15:50:37 GMT

This site is a good resource for string formatting.