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  • python day5

    列表:
    #
    l=[1,2,3] #l=list([1,2,3]) # print(type(l)) #优先掌握 #  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)

    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['name'])
    # 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','sex':'male','age':18,}
    # # info_dic.pop()
    # info_dic.popitem()
    # print(info_dic)
    # del info_dic['name']
    # print(info_dic)
    
    #
    #     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)
    #

    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('===>')
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  • 原文地址:https://www.cnblogs.com/jmblog/p/7212273.html
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