ArcGIS Raster Calculator error 000539 ImportError: No module named numpy?

Question

I am running ArcGIS 10.2.1 on Win7 64bit. I have finished doing an NDVI, and after defining a vegetation presence threshold at 0.05, opened the Raster Calculator (via Map Algebra in the Arc Toolbox) to generate a new raster with a 0 value for no vegetation and a 1 value for vegetation. I'm getting the following error:

Executing: RasterCalculator ""NDVI_ik_06.tif" > 0.05"

ERROR 000539: Error running expression: rcexec() 
Traceback (most recent call last):
  File "<expression>", line 1, in <module>
  File "<string>", line 2, in rcexec
  File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\__init__.py", line 24, in <module>
    from arcpy.toolbox import *
  File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\toolbox.py", line 356, in <module>
    from management import Graph, GraphTemplate
  File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\management.py", line 22, in <module>
    import _management
  File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\_management.py", line 14, in <module>
    import _graph
  File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\_graph.py", line 27, in <module>
    import numpy
ImportError: No module named numpy

Failed to execute (RasterCalculator).
Failed at Tue Apr 07 11:24:48 2015 (Elapsed Time: 0.09 seconds)

Any ideas?

Answer 1

If you see an

ImportError: No module named numpy

in circumstances like you describe, I think the expedient to getting a working ArcGIS for Desktop installation will be to uninstall/reinstall ArcGIS for Desktop to let it take care of installing and referencing the expected Python and NumPy versions.

This should take less than an hour, and I suspect trying to debug a corrupt NumPy/Python installation will take most of us longer than that with no guarantee of success.