Module: testing.decorators_numpy

Decorators for labeling test objects

Decorators that merely return a modified version of the original function object are straightforward. Decorators that return a new function object need to use nose.tools.make_decorator(original_function)(decorator) in returning the decorator, in order to preserve metadata such as function name, setup and teardown functions and so on - see nose.tools for more information.



Signals to nose that this function is or is not a test


tf : bool

If True specifies this is a test, not a test otherwise

This decorator cannot use the nose namespace, because it can be :

called from a non-test module. See also istest and nottest in :

nose.tools :

IPython.testing.decorators_numpy.skipif(skip_condition=True, msg=None)

Make function raise SkipTest exception if skip_condition is true


skip_condition : bool or callable.

Flag to determine whether to skip test. If the condition is a callable, it is used at runtime to dynamically make the decision. This is useful for tests that may require costly imports, to delay the cost until the test suite is actually executed.

msg : string

Message to give on raising a SkipTest exception


decorator : function

Decorator, which, when applied to a function, causes SkipTest to be raised when the skip_condition was True, and the function to be called normally otherwise.


You will see from the code that we had to further decorate the decorator with the nose.tools.make_decorator function in order to transmit function name, and various other metadata.

Decorator to raise SkipTest for test known to fail

Labels a test as ‘slow’.

The exact definition of a slow test is obviously both subjective and hardware-dependent, but in general any individual test that requires more than a second or two should be labeled as slow (the whole suite consits of thousands of tests, so even a second is significant).