numpy.any(a, axis=None, out=None)

Test whether any array element along a given axis evaluates to True.

Returns single boolean unless axis is not None

Parameters :

a : array_like

Input array or object that can be converted to an array.

axis : int, optional

Axis along which a logical OR is performed. The default (axis = None) is to perform a logical OR over a flattened input array. axis may be negative, in which case it counts from the last to the first axis.

out : ndarray, optional

Alternate output array in which to place the result. It must have the same shape as the expected output and its type is preserved (e.g., if it is of type float, then it will remain so, returning 1.0 for True and 0.0 for False, regardless of the type of a). See doc.ufuncs (Section “Output arguments”) for details.

Returns :

any : bool or ndarray

A new boolean or ndarray is returned unless out is specified, in which case a reference to out is returned.

See also

equivalent method
Test whether all elements along a given axis evaluate to True.


Not a Number (NaN), positive infinity and negative infinity evaluate to True because these are not equal to zero.


>>> np.any([[True, False], [True, True]])
>>> np.any([[True, False], [False, False]], axis=0)
array([ True, False], dtype=bool)
>>> np.any([-1, 0, 5])
>>> np.any(np.nan)
>>> o=np.array([False])
>>> z=np.any([-1, 4, 5], out=o)
>>> z, o
(array([ True], dtype=bool), array([ True], dtype=bool))
>>> # Check now that z is a reference to o
>>> z is o
>>> id(z), id(o) # identity of z and o              
(191614240, 191614240)

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