Python中3种内建数据结构:列表、元组和字典
Python中有3种内建的数据结构:列表、元组和字典。参考简明Python教程
列表中的项目应该包括在方括号中,这样Python就知道你是在指明一个列表。一旦你创建了一个列表,你可以添加、删除或是搜索列表中的项目。由于你可以增加或删除项目,我们说列表是 可变的 数据类型,即这种类型是可以被改变的。 #!/usr/bin/env python #coding:utf8 list = ['Linux','Nginx','MySQL','PHP'] print 'These items are:',for item in list: print item,print 'nadd Apache.' list.append('Apache') print 'list is now',list print 'nI will sort my list now' list.sort() print 'Sorted list is %s' % list print 'nThe first item ',list[0] item0 = list[0] print 'delete first item' del list[0] print 'list is now',list 输出 $python using_list.py These items are: Linux Nginx MySQL PHP add Apache. list is now ['Linux','PHP','Apache'] I will sort my list now Sorted list is ['Apache','Linux','PHP'] The first item Apache delete first item list is now ['Linux','PHP'] 2. 元组 #!/usr/bin/env python #coding:utf8 zoo = ('wolf','elephant','penguin') print 'Number of animals in the zoo is',len(zoo) new_zoo = ('monkey','dolphin',zoo) print 'Number of animals in the new zoo is',len(new_zoo) print 'All animals in new zoo are',new_zoo print 'Animals brought from old zoo are',new_zoo[2] print 'Last animal brought from old zoo is',new_zoo[2][2] 输出 $ python using_tuple.py Number of animals in the zoo is 3 Number of animals in the new zoo is 3 All animals in new zoo are ('monkey',('wolf','penguin')) Animals brought from old zoo are ('wolf','penguin') Last animal brought from old zoo is penguin 3. 字典 注意,你只能使用不可变的对象(比如字符串)来作为字典的键,但是你可以不可变或可变的对象作为字典的值。基本说来就是,你应该只使用简单的对象作为键。 键值对在字典中以这样的方式标记:d = {key1 : value1,key2 : value2 }。注意它们的键/值对用冒号分割,而各个对用逗号分割,所有这些都包括在花括号中。 记住字典中的键/值对是没有顺序的。如果你想要一个特定的顺序,那么你应该在使用前自己对它们排序。 字典是dict类的实例/对象。 #!/usr/bin/env python #coding:utf8 contacts = { 'Admin' : 'admin@aspzz.cn','Linuxeye' : 'linuxeye@aspzz.cn','Support' : 'support@aspzz.cn' } print "Linuxeye's address is %s" % contacts['Linuxeye'] # Adding a key/value pair contacts['test'] = 'test@aspzz.cn' # Deleting a key/value pair del contacts['Support'] print 'nThere are %d contacts in the address-bookn' % len(contacts) for name,address in contacts.items(): print 'Contact %s at %s' % (name,address) if contacts.has_key('test'): print "ntest's address is %s" % contacts['test'] 输出 $ python using_dict.py Linuxeye's address is linuxeye@aspzz.cn There are 3 contacts in the address-book Contact Admin at admin@aspzz.cn Contact test at test@aspzz.cn Contact Linuxeye at linuxeye@aspzz.cn test's address is test@aspzz.cn (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |