#範例5-7：串列/數組/列表，list的複製
#https://www.w3schools.com/python/python_lists_copy.asp
#https://www.w3school.com.cn/python/ref_list_copy.asp

#注意1：不可以直接設定list2 = list1, You cannot copy a list simply by typing list2 = list1, 
#原因：because: list2 will only be a reference to list1, and changes made in list1 will automatically also be made in list2.
#結果：改了list2, 也會更動到list1
#解決方法：There are ways to make a copy, one way is to use the built-in List method copy().

#語法：list2 = list1.copy()
#語法：list2 = list(list1)

#-----------------------------
#1.錯誤的複製方法
a1 = ["tom","john","bo","mikewang","jolin","peter"]


#結論：複製list，不可以直接 a2 = a1
#因為，兩個會連動，修改一個，就會改到另外一個

#----------------------------
#2.正確的複製方法(1)
a1 = ["tom","john","bo","mikewang","jolin","peter"]


#-----------------------------
#3.正確的複製方法(2)
a1 = ["tom","john","bo","mikewang","jolin","peter"]



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#範例5-7：串列/數組/列表，list的複製
#https://www.w3schools.com/python/python_lists_copy.asp
#https://www.w3school.com.cn/python/ref_list_copy.asp

#注意1：不可以直接設定list2 = list1, You cannot copy a list simply by typing list2 = list1, 
#原因：because: list2 will only be a reference to list1, and changes made in list1 will automatically also be made in list2.
#結果：改了list2, 也會更動到list1
#解決方法：There are ways to make a copy, one way is to use the built-in List method copy().

#語法：list2 = list1.copy()
#語法：list2 = list(list1)

#1.錯誤的複製方法
a1 = ["tom","john","bo","mikewang","jolin","peter"]
a2 = a1
a2[0] = "top"
print(a1)
print(a2)
#結論：複製list，不可以直接 a2 = a1
#因為，兩個會連動，修改一個，就會改到另外一個

#2.正確的複製方法(1)
a1 = ["tom","john","bo","mikewang","jolin","peter"]
a3 = a1.copy()
a3[0] = "ttt"
print(a3)
print(a1)


#3.正確的複製方法(2)
a1 = ["tom","john","bo","mikewang","jolin","peter"]
a4 = list(a1)
a4[0] = "aaa"
print(a4)
print(a1)



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