Dear all, I am trying to turn Python warnings to errors, but it does not work as expected with numpy. The following two piece of code work: $ python -W error -c 'import warnings; import numpy; warnings.warn("test", numpy.core.numeric.ComplexWarning)' Traceback (most recent call last): File "<string>", line 1, in <module> numpy.core.numeric.ComplexWarning: test $ python -W error -c 'import warnings; import numpy; raise numpy.core.numeric.ComplexWarning' Traceback (most recent call last): File "<string>", line 1, in <module> numpy.core.numeric.ComplexWarning while this does not (i.e. still produces just a warning): $ python -W error -c 'import numpy; x=numpy.ones(2); x+=1j' numpy.core.numeric.ComplexWarning: Casting complex values to real discards the imaginary part This is with Python 2.6.6 and numpy 1.5.1, but also confirmed with Python 2.7. Thanks for any suggested solutions, Ondrej Marsalek