循环
# msg='hello' # msg=[1,2,3,4,5,6] msg=(1,2,3,4,5,6) msg_dic={ 'apple':10, 'tesla':1000000, 'mac':3000, 'lenovo':30000, 'chicken':10, } index=0 while index < len(msg): print(msg[index]) index+=1 msg='hello' # msg=['a','b','c','d','e'] # msg=('a','b','c','d','e') for i in range(len(msg)): print(i,msg[i]) 不依赖索引的取值 for item in msg_dic: print(item,msg_dic[item]) msg='hello' msg=[1,2,3,4,5,6] msg=(1,2,3,4,5,6) for item in msg: print(item) 补充 range:顾头不顾尾，默认从0开始 print(type(range(1,2))) for i in range(10): print(i,type(i)) for i in range(1,10,2): print(i,type(i)) for i in range(10,1,-2): print(i) for i in range(1,10,1): print(i) for i in range(9,0,-1): print(i) break continue for i in range(10): if i == 4: # break continue print(i) for+else for i in range(10): print(i) break else: print('===>')
元组
为何要有元组，存放多个值，元组不可变，更多的是用来做查询 t=(1,[1,3],'sss',(1,2)) #t=tuple((1,[1,3],'sss',(1,2))) print(type(t)) #元组可以作为字典的key d={(1,2,3):'egon'} print(d,type(d),d[(1,2,3)]) 索引 切片 goods=('iphone','lenovo','sanxing','suoyi') print(goods[1:3]) 长度 in: 字符串:子字符串 列表：元素 元组：元素 字典：key goods=('iphone','lenovo','sanxing','suoyi') print('iphone' in goods) d={'a':1,'b':2,'c':3} print('b' in d) 掌握 goods=('iphone','lenovo','sanxing','suoyi') print(goods.index('iphone')) print(goods.count('iphone')) 补充：元组本身是不可变的，但是内部的元素可以是可变类型 t=(1,['a','b'],'sss',(1,2)) #t=tuple((1,[1,3],'sss',(1,2))) t[1][0]='A' print(t) t[1]='aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'
字典
info=['egon','male',18,180,75] info_dic={'name':'egon','age':18,'sex':'male'} 常用操作： 存/取 info_dic={'name':'egon','age':18,'sex':'male'} print(info_dic['name11111111']) print(info_dic.get('name',None)) pop：key存在则弹出值，不存在则返回默认值，如果没有默认值则报错 print(info_dic.pop('nam123123123123123123e',None)) print(info_dic) print(info_dic.popitem()) print(info_dic) info_dic['level']=10 print(info_dic) 删除 info_dic={'name':'egon','age':18,'sex':'male'} info_dic.pop() info_dic.popitem() del info_dic['name'] 键s，值s，键值对 info_dic={'name':'egon','age':18,'sex':'male'} print(info_dic.keys()) print(info_dic.values()) print(info_dic.items()) for k in info_dic: # print(k,info_dic[k]) print(k) print('========>') for k in info_dic.keys(): print(k) for val in info_dic.values(): print(val) for k,v in info_dic.items(): #k,v=('name', 'egon') print(k,v) 长度 info_dic={'name':'egon','age':18,'sex':'male'} print(len(info_dic)) 循环 # 包含in info_dic={'name':'egon','age':18,'sex':'male'} print('name' in info_dic) print('name' in info_dic.keys()) print('egon' in info_dic.values()) print(('name','egon') in info_dic.items()) 掌握 info_dic={'name':'egon','age':18,'sex':'male'} info_dic.update({'a':1,'name':'Egon'}) print(info_dic) info_dic['hobbies']=[] info_dic['hobbies'].append('study') info_dic['hobbies'].append('read') print(info_dic) setdefault:key不存在则设置默认值，并且放回值默认值 key存在则不设置默认，并且返回已经有的值 info_dic.setdefault('hobbies',[1,2]) print(info_dic) info_dic.setdefault('hobbies',[1,2,3,4,5]) print(info_dic) info_dic={'name':'egon','age':18,'sex':'male'} {'name':'egon','age':18,'sex':'male','hobbies':['study']} info_dic.setdefault('hobbies',[]).append('study') {'name':'egon','age':18,'sex':'male','hobbies':['study','read']} info_dic.setdefault('hobbies',[]).append('read') {'name':'egon','age':18,'sex':'male','hobbies':['study','read','sleep']} info_dic.setdefault('hobbies',[]).append('sleep') l=info_dic.setdefault('hobbies',[]) print(l,id(l)) print(id(info_dic['hobbies'])) print(info_dic) 了解 d=info_dic.copy() print(d) info_dic.clear() print(info_dic) d=info_dic.fromkeys(('name','age','sex'),None) print(d) d1=dict.fromkeys(('name','age','sex'),None) d2=dict.fromkeys(('name','age','sex'),('egon',18,'male')) print(d1) print(d2) info=dict(name='egon',age=18,sex='male') print(info) info=dict([('name','egon'),('age',18)]) print(info)
列表
l=[1,2,3] #l=list([1,2,3]) print(type(l)) pat1===》优先掌握部分 索引 切片 l=['a','b','c','d','e','f'] print(l[1:5]) print(l[1:5:2]) print(l[2:5]) print(l[-1]) 了解 print(l[-1:-4]) print(l[-4:]) l=['a','b','c','d','e','f'] print(l[-2:]) 追加 hobbies=['play','eat','sleep','study'] hobbies.append('girls') print(hobbies) 删除 hobbies=['play','eat','sleep','study'] x=hobbies.pop(1) #不是单纯的删除，是删除并且把删除的元素返回，我们可以用一个变量名去接收该返回值 print(x) print(hobbies) x=hobbies.pop(0) print(x) x=hobbies.pop(0) print(x) 队列：先进先出 queue_l=[] #入队 queue_l.append('first') queue_l.append('second') queue_l.append('third') print(queue_l) 出队 print(queue_l.pop(0)) print(queue_l.pop(0)) print(queue_l.pop(0)) 堆栈:先进后出，后进先出 l=[] #入栈 l.append('first') l.append('second') l.append('third') #出栈 print(l) print(l.pop()) print(l.pop()) print(l.pop()) 了解 del hobbies[1] #单纯的删除 hobbies.remove('eat') #单纯的删除，并且是指定元素去删除 长度 hobbies=['play','eat','sleep','study'] print(len(hobbies)) 包含in hobbies=['play','eat','sleep','study'] print('sleep' in hobbies) msg='hello world egon' print('egon' in msg) #pat2===》掌握部分 hobbies=['play','eat','sleep','study','eat','eat'] hobbies.insert(1,'walk') hobbies.insert(1,['walk1','walk2','walk3']) print(hobbies) print(hobbies.count('eat')) print(hobbies) hobbies.extend(['walk1','walk2','walk3']) print(hobbies) hobbies=['play','eat','sleep','study','eat','eat'] print(hobbies.index('eat')) pat3===》了解部分 hobbies=['play','eat','sleep','study','eat','eat'] hobbies.clear() print(hobbies) l=hobbies.copy() print(l) l=[1,2,3,4,5] l.reverse() print(l) l=[100,9,-2,11,32] l.sort(reverse=True) print(l)