• []是引用 傳址調用
• [:] 是復制 傳值調用

發現用b=a[:], 再給b賦值, 不會影響a; 直接給a[:]賦值卻會影響a

a=5b=aprint(a,b)b=3print(a,b)a=6print(a,b)5 5 5 3 6 3c=[1,2,3,4]d=cprint(c,d)c[0]=5print(c,d)d[0]=6print(c,d)[1, 2, 3, 4] [1, 2, 3, 4] [5, 2, 3, 4] [5, 2, 3, 4] [6, 2, 3, 4] [6, 2, 3, 4]c=[1,2,3,4]d=c[:]print(c,d)c[0]=5print(c,d)d[0]=6print(c,d)[1, 2, 3, 4] [1, 2, 3, 4] [5, 2, 3, 4] [1, 2, 3, 4] [5, 2, 3, 4] [6, 2, 3, 4]c=[1,2,[1,2,3],3,4]d=c[:] # 沒有限制條件的分片表達式（L[:]）能夠復制序列，但此法只能淺層復制; 在有嵌套情況跟著一起變化print(c,d)c[0]=5c[2][0]=7print(c,d)d[0]=6print(c,d)[1, 2, [1, 2, 3], 3, 4] [1, 2, [1, 2, 3], 3, 4] [5, 2, [7, 2, 3], 3, 4] [1, 2, [7, 2, 3], 3, 4] [5, 2, [7, 2, 3], 3, 4] [6, 2, [7, 2, 3], 3, 4]import copyc=[1,2,3,4]d=copy.deepcopy(c)print(c,d)c[0]=5print(c,d)d[0]=6print(c,d)[1, 2, 3, 4] [1, 2, 3, 4] [5, 2, 3, 4] [1, 2, 3, 4] [5, 2, 3, 4] [6, 2, 3, 4]a = [0, [1, 2], 3]b = a[:]a[0] = 8a[1][1] = 9print(a,b)[8, [1, 9], 3] [0, [1, 9], 3] ''' 學習中遇到問題沒人解答？小編創建了一個Python學習交流QQ群：531509025 尋找有志同道合的小伙伴，互幫互助,群里還有不錯的視頻學習教程和PDF電子書！ ''' import copya = [0, [1, 2], 3]b = copy.deepcopy(a)a[0] = 8a[1][1] = 9print(a,b)[8, [1, 9], 3] [0, [1, 2], 3]

總結

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