is判断是否为同一个对象，即判断是否引用了同一个内存地址。内存地址可以使用id(obj)获取。
==判断值是否相等。
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import copy a = 1 b = 1 print(a == b) # True print(a is b) # True a = [] b = [] print(a == b) # True print(a is b) # False b = a print(a == b) # True print(a is b) # True b = copy.deepcopy(a) print(a == b) # True print(a is b) # False print("*" * 10) a = [1, 2, 3] b = [4, 5, 6] c = [a, b] # 列表c存储的是a和b的引用，而不是元素 print(c) # [[1, 2, 3], [4, 5, 6]] b.append(9) print(c) # [[1, 2, 3], [4, 5, 6, 9]] print("*" * 10) a = [1, 2, 3] b = [4, 5, 6] c = [a, b] # 列表c存储的也是a和b的引用 d = copy.deepcopy(c) print("c地址：{}，d地址：{}，c[0]-a地址：{}，d[0]地址：{}".format(id(c), id(d), id(c[0]), id(d[0]))) # c地址：4341183944，d地址：4340997320，c[0]-a地址：4341094920，d[0]地址：4341095944 print(c[1] == d[1]) # True print(c[1] is d[1]) # False。deepcopy-深拷贝对内部引用的对象也进行了拷贝，即创建了新的a和b print(d) # [[1, 2, 3], [4, 5, 6]] a.append(7) print(d) # [[1, 2, 3], [4, 5, 6]] print(c) # [[1, 2, 3, 7], [4, 5, 6]] d[0].append(8) print(d) # [[1, 2, 3, 8], [4, 5, 6]] print(c) # [[1, 2, 3, 7], [4, 5, 6]] print("*" * 10) a = [1, 2, 3] b = [4, 5, 6] c = (a, b) # 元组c存储的也是a和b的引用 d = copy.deepcopy(c) print(d) # ([1, 2, 3], [4, 5, 6]) d[0].append(8) print(d) # ([1, 2, 3, 8], [4, 5, 6]) print(c) # ([1, 2, 3], [4, 5, 6]) b.append(9) print(d) # ([1, 2, 3, 8], [4, 5, 6]) print(c) # ([1, 2, 3], [4, 5, 6, 9]) print("*" * 10) a = [1, 2, 3] b = [4, 5, 6] c = [a, b] # [[1, 2, 3], [4, 5, 6]] d = copy.copy(c) print(c == d) # True print(c is d) # False print("c地址：{}，d地址：{}，c[0]-a地址：{}，d[0]地址：{}".format(id(c), id(d), id(c[0]), id(d[0]))) # c地址：4359120136，d地址：4358933576，c[0]-a地址：4358933704，d[0]地址：4358933704 print(c[1] == d[1]) # True print(c[1] is d[1]) # True。copy-浅拷贝并未创建新的内部引用，仍使用原有的a和b a.append(7) print(c) # [[1, 2, 3, 7], [4, 5, 6]] print(d) # [[1, 2, 3, 7], [4, 5, 6]] print("*" * 10) a = [1, 2, 3] b = [4, 5, 6] c = (a, b) # ([1, 2, 3], [4, 5, 6]) d = copy.copy(c) print(c == d) # True print(c is d) # True print("c地址：{}，d地址：{}，c[0]-a地址：{}，d[0]地址：{}".format(id(c), id(d), id(c[0]), id(d[0]))) # c地址：4360060296，d地址：4360060296，c[0]-a地址：4360117064，d[0]地址：4360117064 print(c[1] == d[1]) # True print(c[1] is d[1]) # True a.append(7) print(c) # [[1, 2, 3, 7], [4, 5, 6]] print(d) # [[1, 2, 3, 7], [4, 5, 6]] # ### 元组是不可变类型。copy.copy(tuple)浅拷贝的操作等同于等号=，直接引用原有的对象 ### |
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本文由崔维友 威格灵 cuiweiyou vigiles cuiweiyou 原创，转载请注明出处：http://www.gaohaiyan.com/2657.html
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