matlab isempty() function in numpy?
For checking if an array is empty (that is, it doesn't contain any elements), you can use A.size == 0:
import numpy as npIn [2]: A = np.array([[1, 2], [3, 4]])In [3]: A.sizeOut[3]: 4In [4]: B = np.array([[], []])In [5]: B.sizeOut[5]: 0To check whether it only contains 0's you can check for np.count_nonzero(A):
In [13]: Y = np.array([[0, 0], [0, 0]])In [14]: np.count_nonzero(Y)Out[14]: 0
>>> empty_array = np.zeros((3,3))>>> empty_arrayarray([[ 0., 0., 0.], [ 0., 0., 0.], [ 0., 0., 0.]])>>> if np.all(empty_array==0): print True... True>>> empty_array[1][1]=1>>> empty_arrayarray([[ 0., 0., 0.], [ 0., 1., 0.], [ 0., 0., 0.]])>>> if np.all(empty_array==0): ... print True... else:... print False... False