#定义一个列表 classmates =['lucy','Bob','amy','陈四','tom',65] new = ['Tim','Chenjie'] #向classmates中下标为2处插入一个元素 classmates.insert(2,'Wuyifan') #使用append向末尾增加一个元素 classmates.append('Chenjie') classmates.extend(new) print(classmates) classmatesSet = set(classmates) classmatesSet.add('Chenjie') print(classmatesSet) print(list('acadswet'),tuple('ababcd'))
#列表的遍历 List1=['Tim',30,'Tom',20] print(List1) for one in List1: print(one) #元组的遍历 Tuple1=('我要当歌手!') print(Tuple1) for two in Tuple1: print(two) #集合的遍历 Set1={4,5,6,7} print(Set1) for three in Set1: print(three) #字典的遍历 dict1 = {'a':10,'b':20,'c':30} print(dict1) for four in dict1: print(four,dict1[four])
总结列表,元组,字典,集合的联系与区别:
列表:有序,可做增删改查操作,用方括号[x,y,z]的方式表示
元组:有序,不可做修改操作,用小括号(x,y,z)的方式表示
字典:无序,可做增删改查操作,其中组成元素为键值对,用花括号{a:b,c:d}的方式表示
集合:无序,可由列表创建,其中元素不重复,用花括号{x,y,z}的方式表示
英文词频统计:
str='''If I should stay I would only be in your way So I'll go But I know I'll think of your every step of the way And I will always love you Will always love you You my darling you Bitter-sweet memories That is all I'm taking with me So goodbye Please don't cry We both know I'm not What you need And I will always love you I will always love you I hope life treats you kind And I hope you have all you dreamed of And I wish you joy and happiness But above all this Ii wish your love And I will always love you I will always love you I will always love you I will always love you I will always love you I will always love you Darling I love you I'll always love you''' #每个单词的第二个以后都变成小写 a=str.lower() print(a) #删除空格 str=str.lstrip() print(str) #分隔出一个一个的单词 list print("将歌词分隔一个一个的单词为:") strlist=str.split() print(strlist) #统计每个单词出现的次数 dict print("统计每个单词出现的次数为:") strset=set(strlist) for word in strset: print(word,strlist.count(word))