Steward_Xu

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一、python运算符:

  

二、数据类型:

   1、数字:

    int  :整型

      32位机器上一个整数取值范围为-2**31~2**31-1-2147483648~2147483647

      64位机器上一个整数取值范围为-2**63~2**63-1-9223372036854775808~~9223372036854775807

    Long:长整型

      Float:浮点型

   2、布尔值

      0或者1;真或者假

   3、字符串

      移除空白(lstrip;rstrip)

  

    
a = " adfadf "
spcae = a.lstrip()    #移除左边空白
print(spcae)

a = " adfadf "
spcae = a.rstrip()   #移除右边空白
print(spcae)
去除空白

    分割(split

    

    
1 a = " adfadfce "
2 spcae = a.split("f",1)
3 print(spcae)
View Code

 

 

    长度(__len__()

    索引()

    a = " adfadfce "  #前后是有空格的

    spcae = a[-4]

    f

         切片

    

    
1 a = " adfadfce "
2 spcae = a[1::2]  #表示以步长去切片。取出来的值为afdc 
3 a = " adfadfce "
4 spcae = a[:7]     #表示从头开始到第六个位,不包含7。取出来的值为 adfadf备注最前面有个空格的字符。
切片

  4、列表:

    创建列表:

    

    
1 #name_list = [ 'xxd','yb','wc','hwq', ]
2 name_list = list ([ 'xxd','yb','wc','hwq', ])
3 print(name_list)
创建列表

 

    索引

    

    
 1 #name_list = [ 'xxd','yb','wc','hwq', ]
 2 name_list = list ([ 'xxd','yb','wc','hwq', ])
 3 #print(name_list)
 4 name_index = name_list[0]      #表示第一个元素0表示第一个元素
 5 name_index1 = name_list[1]     #表示第二个元素
 6 name_index2 = name_list[2]     #表示第三个元素
 7 name_index3 = name_list[1:3]    #表示第二个元素到底三个元素,三表示第四个元素但是不含,所以实际上是不包含第四个元素hwq
 8 print(name_index)
 9 print(name_index1)
10 print(name_index2)
11 print(name_index3)
12 输出的结果是:
13 xxd
14 yb
15 wc
16 ['yb', 'wc']
索引

 

    切片

    

    
 1 name_list = [ 'xxd','yb','wc','hwq','gk','cp','tc' ]
 2 name_spl = name_list[0:1]
 3 name_spl2 = name_list[4:]
 4 name_spl3 = name_list[3:5]
 5 print(name_spl)
 6 print(name_spl2)
 7 print(name_spl3)
 8 结果运行
 9 ['xxd']
10 ['gk', 'cp', 'tc']
11 ['hwq', 'gk']
12 其实规则与之前的类似这里不累述:
切片

 

    追加(append)

    

    
1 name_list = [ 'xxd','yb','wc','hwq','gk','cp','tc' ]
2 name_list.append('ysl');
3 print(name_list)
4 
5 运行结果:
6 ['xxd', 'yb', 'wc', 'hwq', 'gk', 'cp', 'tc', 'ysl']  末尾追加了ysl
追加

   

    删除

    

 1 name_list = [ 'xxd','yb','wc','hwq','gk','cp','tc' ]
 2 del name_list[3]     #删除第四个元素.
 3 print(name_list)
 4 结果是:
 5 ['xxd', 'yb', 'wc', 'gk', 'cp', 'tc']
 6 
 7 name_list = [ 'xxd','yb','wc','hwq','gk','cp','tc' ]
 8 #del name_list[3]
 9 name_list.pop()        #删除最后一位。
10 print(name_list)
11 结果:
12 ['xxd', 'yb', 'wc', 'hwq', 'gk', 'cp']
13 
14 
15 name_list = [ 'xxd','yb','wc','hwq','gk','cp','tc' ]
16 #del name_list[3]
17 #name_list.pop()
18 name_list.remove('xxd')   #删除指定的元素xxd
19 print(name_list)
20 输出结果:
21 ['yb', 'wc', 'hwq', 'gk', 'cp', 'tc']

 

    长度

    

    
1 name_list = [ 'xxd','yb','wc','hwq','gk','cp','tc' ]
2 LENth = len(name_list)
3 print(LENth)
4 
5 结果:
6 
7 7
长度

    包含

    

    
 1 name_list = [ 'xxd','yb','wc','hwq','gk','cp','tc' ]
 2 user = 'xxd'
 3 print (user in name_list)
 4 结果:
 5 true    因为xxd包含在了列表中
 6 
 7 
 8 name_list = [ 'xxd','yb','wc','hwq','gk','cp','tc' ]
 9 user = 'yyd'
10 print (user in name_list)
11 结果为:
12 false   因为yyd包含在了列表中
包含

  5、元组:

    创建:

    
1 ages = (11, 22, 33, 44, 55)
2 3 ages = tuple((11, 22, 33, 44, 55))
View Code

    元组与列表相似,只是没有了修改的功能,可以参考列表操作:索引、切片、长度、包含

  6、字典:

    创建:

    

     
1 place = {"sheng":"sichuang",'shenghui':"chengdu"}
2 或者
3 place = dict{"sheng":"sichuang",'shenghui':"chengdu"}
View Code

    索引:

    

   
    
1 place = {"sheng":"sichuan",'shenghui':"chengdu"}
2 print(place['shenghui'])
3 place = {"sheng":['sichuan','yunnan','guizhou','shanxi','xizang',],'diqu':['east','south','west','north',]}
4 print(place['diqu'])
5 结果:
6 "chengdu"
7 
8 ['east','south','west','north',]
View Code

 

      新增

    

    
1 place = {"sheng":['sichuan','yunnan','guizhou','shanxi','xizang',],'diqu':['east','sout
2 place['zhou'] = ['Asia','Amaric','Eu']
3 print(place)
4 结果在输出中含有:
5 'zhou': ['Asia', 'Amaric', 'Eu']
View Code

     新增还有append参考列表

    删除:

    del adict[key] 删除键key的项 / del adict 删除整个字典/adict.pop(key) 删除键key的项并返回key对应的 value值

    

    
1 place = {'diqu': ['east', 'south', 'west', 'north'], 'zhou': ['Asia', 'Amaric', 'Eu'], 'sheng': ['sichuan', 'yunnan', 'guizhou', 'shanxi', 'xizang']}
2 del place['zhou']
3 print(place)
4 显示结果已经删除了 'zhou': ['Asia', 'Amaric', 'Eu'],'
5 {'diqu': ['east', 'south', 'west', 'north'], 'sheng': ['sichuan', 'yunnan', 'guizhou', 'shanxi', 'xizang']}
6 place = {'diqu': ['east', 'south', 'west', 'north'], 'zhou': ['Asia', 'Amaric', 'Eu'], 'sheng': ['sichuan', 'yunnan', 'guizhou', 'shanxi', 'xizang']}
7 place.pop('zhou')
8 print(place)
View Code

 

    键、值、键值对

    循环

    长度len()

    

    
1 place = {"sheng":['sichuan','yunnan','guizhou','shanxi','xizang',],'diqu':['east','sout']}
2 print len(place)
View Code

 

    

posted on 2017-04-16 17:46  Steward_Xu  阅读(628)  评论(0编辑  收藏  举报