python之array赋值技巧分享

import numpy as np

list_a = list(range(10))
print("list_a: {}".format(list_a))

array_a = np.array(list_a)
print("array_a: {}".format(array_a))

list_b = [True,False,True,True,False,False,True,False,True,False]
print("list_b: {}".format(list_b))

array_b = np.array(list_b)
print("array_b: {}".format(array_b))

mask = np.zeros(10,dtype=np.bool)
print("mask: {}".format(mask))

list_a: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
array_a: [0 1 2 3 4 5 6 7 8 9]
list_b: [True, False, True, True, False, False, True, False, True, False]
array_b: [ True False True True False False True False True False]
mask: [False False False False False False False False False False]

d = array_a[list_b]
print("array_a[list_b]: {}".format(d))

e = array_a[array_b]
print("array_a[array_b]: {}".format(e))

mask[list_b] = 1
print("mask: {}".format(mask))

array_a[list_b]: [0 2 3 6 8]
array_a[array_b]: [0 2 3 6 8]
mask: [ True False True True False False True False True False]

d = list_a[list_b]
TypeError: list indices must be integers or slices, not list

e = list_a[array_b]
TypeError: only integer scalar arrays can be converted to a scalar index