作业来源于:https://edu.cnblogs.com/campus/gzcc/GZCC-16SE2/homework/2696
1.列表,元组,字典,集合分别如何增删改查及遍历。
1.列表
1 list = ['wang','li','chen'] 2 list.append('huang') 3 print(list) 4 #末尾插入元素 5 list = ['wang','li','chen'] 6 list.insert(2,'huang') 7 print(list) 8 #元素插入指定位置 9 list = ['wang','li','chen'] 10 list.remove('li') 11 print(list) 12 #按名称删除元素 13 list = ['wang','li','chen'] 14 list.pop(1) 15 print(list) 16 #按位置删除元素 17 list = ['wang','li','chen'] 18 list[1] = 'huang' 19 print(list) 20 #按位置修改元素 21 list = ['wang','li','chen'] 22 print(list[1]) 23 #查找元素 24 list = ['wang','li','chen'] 25 for bl in list: 26 print("序号:{} {}".format(list.index(bl),bl)) 27 #遍历
2.元组
1 ob = ('wang','li') 2 ob2 = ('chen','huang') 3 ob3 = ob + ob2 4 print(ob3) 5 #添加元素 6 ob3 = ('wang','li','chen','huang') 7 print("第一个:{} 第二个:{}".format(ob3[0],ob3[1])) 8 #查找指定元素 9 ob = ('wang','li') 10 print("元组删除") 11 del ob 12 #元组删除 13 ob3 = ('wang','li','chen','huang') 14 for bl in ob3: 15 print(bl) 16 #遍历元组
3.字典
1 dict = {'wang':100,'li':90,'chen':80} 2 dict['huang'] = 70 3 print(dict) 4 #添加元素 5 dict = {'wang':100,'li':90,'chen':80} 6 del dict['wang'] 7 print(dict) 8 #删除元素 9 dict = {'wang':100,'li':90,'chen':80} 10 dict.pop('wang') 11 print(dict) 12 #删除元素 13 dict = {'wang':100,'li':90,'chen':80} 14 dict['wang'] = 99 15 print(dict) 16 #修改元素 17 dict = {'wang':100,'li':90,'chen':80} 18 print("查找的人:{}".format(dict['wang'])) 19 #查找元素 20 dict = {'wang':100,'li':90,'chen':80} 21 for bl in dict: 22 print("{}:{}".format(bl,dict[bl])) 23 #遍历字典
4.集合
1 s = set(['wang','li','chen']) 2 s.add('huang') 3 print(s) 4 #添加元素 5 s = set(['wang','li','chen']) 6 s.remove('wang') 7 print(s) 8 #删除元素 9 s = set(['wang','li','chen']) 10 s = list(s) 11 s[0] = 'huang' 12 s = set(s) 13 print(s) 14 #修改元素 15 s = set(['wang','li','chen']) 16 s.clear() 17 print(s) 18 s = set(['wang','li','chen']) 19 for bl in s: 20 print(bl) 21 #遍历
2.总结列表,元组,字典,集合的联系与区别。参考以下几个方面:
- 括号
列表:[ ]
元组:( )
字典:{ }
集合:( ) - 有序无序
列表:有
元组:有
字典:无
集合:无 - 可变不可变
列表:可变
元组:不可变
字典:不可变
集合:可变 - 重复不可重复
列表:重复
元组:重复
字典:不可重复
集合:不可重复 - 存储与查找方式
列表:按照一定顺序编写,通过偏移读取
元组:与列表差不多
字典:存储的是对象引用,不是拷贝,和列表一样
集合:与列表差不多
3.词频统计
1 f = open(r'D:pyhomeworkigbigword.txt',encoding='utf8') 2 #打开文件 3 stop={'a','the','and','i','you','in','but','not','with','by','its','for','of','an','to','my','myself','we','our','ours','ourelves','about','no','nor'} 4 def gettext(): 5 sep = "~`*()!<>?,./;':[]{}-=_+" 6 text = f.read().lower() 7 for s in sep: 8 text=text.replace(s,'') 9 return text 10 #读取文件 11 textList = gettext().split() 12 print(textList) 13 #分解提取单词 14 textSet = set(textList) 15 stop = set(stop) 16 textSet = textSet - stop 17 print(textSet) 18 #排除语法词 19 textDict = {} 20 for word in textSet: 21 textDict[word] = textList.count(word) 22 print(textDict) 23 print(textDict.items()) 24 word = list(textDict.items()) 25 #单词计数 26 word.sort(key=lambda x:x[1],reverse=True) 27 print(word) 28 #排序 29 for q in range(20): 30 print(word[q]) 31 #次数为前20的单词 32 33 import pandas as pd 34 pd.DataFrame(data=word).to_csv("text.csv",encoding='utf-8')