淺拷貝 shallow copy 和深拷貝 deep copy
list.copy() 淺拷貝：復制此列表(只復制一層，不會復制深層對象) 等同於 L[:]
舉例：
淺拷貝：
a = [1.1, 2.2] # a = [1.1, 2.2]
b = [1, 2, a] # b = [1, 2, [1.1, 2.2]]
c = b.copy() # c = [1, 2, [1.1, 2,2]]
a[0] = 1.123
b = [1, 2, [1.123, 2.2]]
c = [1, 2, [1.123, 2.2]]
內存中的指向是這樣的，如下圖：
深拷貝：
注：使用deepcoyp前需要導入copy模塊。
Import copy # 導入copy模塊
a = [1.1, 2.2] # a = [1.1, 2.2]
b = [1, 2, a] # b = [1, 2, [1.1, 2.2]]
c = b.deepcopy() # c = [1, 2, [1.1, 2,2]]
a[0] = 1.123
b = [1, 2, [1.123, 2.2]]
c = [1, 2, [1.1, 2.2]]
內存中的指向是這樣的，如下圖：
