ArcPy MosaicToNewRaster problem

Question

I can't seem to get the mosaic created for this.

 import arcpy

 arcpy.env.workspace = r"C:\projectTemp\FloodAnalysis\output\2yr\raster"
 arcpy.env.overwriteOutput = True
 srName = r"C:\projectTemp\FloodAnalysis\output\2yr\raster"
 outPut = r"C:\projectTemp\FloodAnalysis\output\2yr"
 rasterName = "2ft.img"
 bands = 1
 method = "First"
 clMap = "First"

 arcpy.MosaicToNewRaster_management(srName, outPut, rasterName, "", "", "", bands,      "First", "First")

Answer 1

You have to enter the parameters in the correct order when using Python. From the ArcGIS 10.2 help page, the following is the correct format:

MosaicToNewRaster_management (input_rasters, output_location, raster_dataset_name_with_extension, {coordinate_system_for_the_raster}, {pixel_type}, {cellsize}, number_of_bands, {mosaic_method}, {mosaic_colormap_mode})

Usually, you bring a list of rasters in the following type of comma-separated list:

[inputRasters, ...]

You can use arcpy.ListRasters() to produce a list of all of the rasters in your workspace that you would like to mosaic:

arcpy.env.workspace = r"C:\projectTemp\FloodAnalysis\output\2yr\raster"
rasters = arcpy.ListRasters()

And to put it all together (In this untested script):

import arcpy

arcpy.env.workspace = r"C:\projectTemp\FloodAnalysis\output\2yr\raster"
arcpy.env.overwriteOutput = True

# Local Variables
outPut = r"C:\projectTemp\FloodAnalysis\output\2yr"
name = "yourOutput.img"
"""Note, there are multiple ways to define a spatial reference,
here I am pointing to a .prj"""
sr = r"C:\path\to\prj\file.prj"
bands = 1
method = "First"
clMap = "First"

# Create raster list
rasters = arcpy.ListRasters()

arcpy.MosaicToNewRaster_management(rasters, outPut, name, sr, "", "", bands, method, clMap)