python基础-set、各个数据类型转换、深浅拷贝

转换

举个列表 字典的转换

x=dict([("x",1),("y",2)])print(x)

输出如下

{'x': 1, 'y': 2}

set集合

set = {3,"Braay",True,(1,2,4)}print(set)print("---------#集合的增--")set1 = {'alex','wusir','ritian','egon','barry'}set1.add('景女神')print(set1)#update：迭代着增加set1.update('A')print(set1)set1.update('老师')print(set1)set1.update([1,2,3])print(set1)print("---------集合的删---")#3，集合的删。set1 = {'alex','wusir','ritian','egon','barry'}set1.remove('alex')  # 删除一个元素print(set1)set1.pop()  # 随机删除一个元素print(set1)set1.clear()  # 清空集合print(set1)# del set1  # 删除集合# print(set1)print("############交集#####")set1 = {1,2,3,4,5}set2 = {4,5,6,7,8}print(set1 & set2)  # {4, 5}print(set1.intersection(set2))  # {4, 5}print("############并集#####")set1 = {1,2,3,4,5}set2 = {4,5,6,7,8}print(set1 | set2)  # {1, 2, 3, 4, 5, 6, 7}print(set2.union(set1))  # {1, 2, 3, 4, 5, 6, 7}print("############差集。（- 或者 difference）#####")set1 = {1,2,3,4,5}set2 = {4,5,6,7,8}print(set1 - set2)  # {1, 2, 3}print(set1.difference(set2))  # {1, 2, 3}print("###########反交集#####")set1 = {1,2,3,4,5}set2 = {4,5,6,7,8}print(set1 ^ set2)  # {1, 2, 3, 6, 7, 8}print(set1.symmetric_difference(set2))  # {1, 2, 3, 6, 7, 8}print("###########子集与超集#####")set1 = {1,2,3}set2 = {1,2,3,4,5,6}print(set1 < set2)print(set1.issubset(set2))  # 这两个相同，都是说明set1是set2子集。print(set2 > set1)print(set2.issuperset(set1))  # 这两个相同，都是说明set2是set1超集。print("######frozenset不可变集合，让集合变成不可变类型,没有增加操作#####")s = frozenset('barry')prin`(s,type(s))  # frozenset({'a', 'y', 'b', 'r'}) <class 'frozenset'>

输出如下：

E:\python\python_sdk\python.exe E:/python/py_pro/demo.py{True, 3, 'Braay', (1, 2, 4)}---------#集合的增--{'alex', 'barry', '景女神', 'ritian', 'wusir', 'egon'}{'alex', 'A', 'barry', '景女神', 'ritian', 'wusir', 'egon'}{'alex', 'A', 'barry', '老', '景女神', 'ritian', 'wusir', '师', 'egon'}{1, 2, 3, 'alex', 'A', 'barry', '老', '景女神', 'ritian', 'wusir', '师', 'egon'}---------集合的删---{'barry', 'ritian', 'wusir', 'egon'}{'ritian', 'wusir', 'egon'}set()############交集#####{4, 5}{4, 5}############并集#####{1, 2, 3, 4, 5, 6, 7, 8}{1, 2, 3, 4, 5, 6, 7, 8}############差集。（- 或者 difference）#####{1, 2, 3}{1, 2, 3}###########反交集#####{1, 2, 3, 6, 7, 8}{1, 2, 3, 6, 7, 8}###########子集与超集#####TrueTrueTrueTrue######frozenset不可变集合，让集合变成不可变类型,没有增加操作#####frozenset({'b', 'a', 'r', 'y'}) <class 'frozenset'>Process finished with exit code 0

深浅copy

#先看赋值运算。l1 = [1,2,3,["aa","bb"]]l2 = l1print(l1)print(l2)l1[0] = 111print(l1)print(l2)#对于赋值运算来说，l1与l2指向的是同一个内存地址，所以他们是完全一样的。l1[3][0] = "wusir"print(l1)print(l2)#浅拷贝copy# 对于浅copy来说，第一层创建的是新的内存地址# 而从第二层开始，指向的都是同一个内存地址# 所以，对于第二层以及更深的层数来说，保持一致性print("---------------------")l1 = [1, 2, 3, ['barry', 'alex']]l2 = l1.copy()print(l1, id(l1))  # [1, 2, 3, ['barry', 'alex']] 2380296895816print(l2, id(l2))  # [1, 2, 3, ['barry', 'alex']] 2380296895048l1[1] = 222print(l1, id(l1))  # [1, 222, 3, ['barry', 'alex']] 2593038941128print(l2, id(l2))  # [1, 2, 3, ['barry', 'alex']] 2593038941896l1[3][0] = 'wusir'print(l1, id(l1[3]))  # [1, 2, 3, ['wusir', 'alex']] 1732315659016print(l2, id(l2[3]))  # [1, 2, 3, ['wusir', 'alex']] 1732315659016

输出如下：

E:\python\python_sdk\python.exe E:/python/py_pro/demo.py[1, 2, 3, ['aa', 'bb']][1, 2, 3, ['aa', 'bb']][111, 2, 3, ['aa', 'bb']][111, 2, 3, ['aa', 'bb']][111, 2, 3, ['wusir', 'bb']][111, 2, 3, ['wusir', 'bb']]---------------------[1, 2, 3, ['barry', 'alex']] 44563432[1, 2, 3, ['barry', 'alex']] 44564112[1, 222, 3, ['barry', 'alex']] 44563432[1, 2, 3, ['barry', 'alex']] 44564112[1, 222, 3, ['wusir', 'alex']] 44563312[1, 2, 3, ['wusir', 'alex']] 44563312Process finished with exit code 0

深拷贝

import copyl1 = [1,2,3,['barry','alex']]l2 = copy.deepcopy(l1)print(l1,id(l1))  # [1, 2, 3, ['barry', 'alex']] 2915377167816print(l2,id(l2))  # [1, 2, 3, ['barry', 'alex']] 2915377167048l1[1] = 222print(l1,id(l1))  # [1, 222, 3, ['barry', 'alex']] 2915377167816print(l2,id(l2))  # [1, 2, 3, ['barry', 'alex']] 2915377167048l1[3][0] = 'wusir'print(l1,id(l1[3]))  # [1, 222, 3, ['wusir', 'alex']] 2915377167240print(l2,id(l2[3]))  # [1, 2, 3, ['barry', 'alex']] 2915377167304

E:\python\python_sdk\python.exe E:/python/py_pro/demo.py[1, 2, 3, ['barry', 'alex']] 59473712[1, 2, 3, ['barry', 'alex']] 59548256[1, 222, 3, ['barry', 'alex']] 59473712[1, 2, 3, ['barry', 'alex']] 59548256[1, 222, 3, ['wusir', 'alex']] 59473472[1, 2, 3, ['barry', 'alex']] 59548216Process finished with exit code 0

对于深copy来说，两个是完全独立的，改变任意一个的任何元素（无论多少层），另一个绝对不改变。