Sorry if I'm being a hassle! I converted some of my rasters to TIF just to mess with before I got your reply and have been just trying to get this to run, but I am getting the error shown below that says my input value raster isn't the right format or doesn't exist. The script is a little different since I have tweaked some things, but if you could take a look and see if you can tell what the problem is that would be great!
>>> import arcpy, os
... from arcpy import env
... from arcpy.sa import *
...
... rasterWorkspace = r"C:\Users\AmyShipley\Desktop\Offline_2014_GIS\Exp_Height_test_TIFF"
... polygonWorkspace = r"C:\Users\AmyShipley\Desktop\Offline_2014_GIS\shp_files\Distance_Buffers\Span_IDx10m_test_group"
...
... env.workspace = polygonWorkspace
... shapefiles = arcpy.ListFeatureClasses("*", "Polygon")
...
... env.workspace = rasterWorkspace
... rasters = arcpy.ListRasters("*", "TIF")
...
... for shapefile in shapefiles:
... shapefileName = shapefile.split(".")[0]
... for raster in rasters:
... rasterName = raster.split(".")[0]
... if rasterName == shapefileName:
... outZonalStats = ZonalStatistics(shapefileName, "FID", rasterName, "MINIMUM", "DATA")
... outZonalStats.save("zs_" + shapefileName)
...
Runtime error Traceback (most recent call last): File "<string>", line 19, in <module> File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\sa\Functions.py", line 6145, in ZonalStatistics ignore_nodata) File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\sa\Utils.py", line 47, in swapper result = wrapper(*args, **kwargs) File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\sa\Functions.py", line 6138, in Wrapper ignore_nodata) File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\geoprocessing\_base.py", line 498, in <lambda> return lambda *args: val(*gp_fixargs(args, True)) ExecuteError: Failed to execute. Parameters are not valid. ERROR 000860: Input value raster: is not the type of Composite Geodataset, or does not exist. Failed to execute (ZonalStatistics).