Обнулить все индексы <0,5, </p>
>>> x3 = np.random.rand(5, 5)
>>> x3
array([[0.50866152, 0.56821455, 0.88531855, 0.36596337, 0.08705278],
[0.96215686, 0.19553668, 0.15948972, 0.20486815, 0.74759719],
[0.36269356, 0.54718917, 0.66196524, 0.82380099, 0.77739482],
[0.0431448 , 0.47664036, 0.80188153, 0.8099637 , 0.65258638],
[0.84862179, 0.22976325, 0.03508076, 0.72360136, 0.76835819]])
>>> x3[x3 < .5] = 0
>>> x3
array([[0.50866152, 0.56821455, 0.88531855, 0. , 0. ],
[0.96215686, 0. , 0. , 0. , 0.74759719],
[0. , 0.54718917, 0.66196524, 0.82380099, 0.77739482],
[0. , 0. , 0.80188153, 0.8099637 , 0.65258638],
[0.84862179, 0. , 0. , 0.72360136, 0.76835819]])