numpy常用概念（copy， deepcopy）
阿新 • • 發佈：2019-01-07
import numpy as np
賦值（物件引用）
a = np.array([1, 2, 3, 4])
a
array([1, 2, 3, 4])
b = a
b
array([1, 2, 3, 4])
a[2] = 0
a
array([1, 2, 0, 4])
b
array([1, 2, 0, 4])
b[1] = 0
a
array([1, 0, 0, 4])
c = b[1:3]
c
array([0, 0])
c[1] = 2
c
array([0, 2])
a
array([1, 0, 2, 4])
b
array([1, 0, 2, 4])
copy(物件拷貝，淺拷貝)
a = np.array([1, 2, 3, 4])
b = a.copy()
b
array([1, 2, 3, 4])
b[0] = 0
b
array([0, 2, 3, 4])
a
array([1, 2, 3, 4])
deepcopy(物件拷貝，深拷貝)
a = [1, 2, 3, 4, ['a', 'b']] #原始物件
d = copy.deepcopy(a) #物件拷貝，深拷貝
d
[1, 2, 3, 4, ['a', 'b']]