Batch_Extract_By _Maskes with one raster and multiple shapefiles

Hi All, I am very noob to python scripting and today i figure i take a crack trying to write a script but for some reason my script does not work. Essentially, I'm trying to extract a DEM Raster file with many shapefiles but when I ran the following scripts, nothing happens at all in my python idle.

here's my script and if anyone can give me a hand I will be greatly appreciated!


# ---------------------
# Extracts raster file by numerous shapefiles
# defined by a mask.
# Author:
# Date: 02/25/2013
# -----------------------------




# Import system modules
import sys, string, os, arcgisscripting

# Create the Geoprocessor object
gp = arcgisscripting.create()

try:
# Check out any necessary licenses
gp.CheckOutExtension("spatial")

# Load required toolboxes...
gp.AddToolbox("C:\Program Files (x86)\ArcGIS\Desktop10.0\ArcToolbox\Toolboxes\Spatial Analsyt Tools.tbx")

gp.workspace = "D:\SH Personal Project\FSWTA\PKI\Individual_watersheds.gdb"
out_workspace = "D:\SH Personal Project\FSWTA\PKI\Clipped_Ind_FSW_WatershedDEMS.gdb"
DEM_Mosaic = "D:\SH Personal Project\FSWTA\PKI\Clipped_WatershedDEM.gdb\Clipped_FSW_WatershedDEM"

# Get a list of the shapefiles in the workspace
shapes = gp.ListFeatureClasses()

# Loop through the list of shapefiles
shapes.reset()
shape = shapes.next()

while shape:
# Set the outputname for each output to be the same as the input
output = out_workspace + shape

# Process: Extract by Mask...
gp.ExtractByMask_sa(Watershed_DEMS, shape, output)

# Loop
shape = shapes.next()

except:
# If an error occurred while running a tool, then print the messages.
print "Error in script"
print gp.GetMessages()