2.30
import numpy as np
a = np.array([[0, 3, 4],
[1, 6, 4]])
b = a.sum()
c1 = sum(a)
c2 = np.sum(a, axis=0)
c3 = np.sum(a, axis=0, keepdims=True)
print(c2.shape, c3.shape)
print('3006')
import numpy as np
a = np.array([[0, 3, 4],
[1, 6, 4]])
b = a.sum()
c1 = sum(a)
c2 = np.sum(a, axis=0)
c3 = np.sum(a, axis=0, keepdims=True)
print(c2.shape, c3.shape)
print('3006')