python学习语句总结

 1 # f=open('a.txt','w',encoding='utf-8')
 2 #
 3 # f.write('11111\n')
 4 # f.write('2222\n')
 5 # f.write('3333\n4444\n')
 6 #
 7 # f.writelines(['a\n','b\n','c\n'])
 8 #
 9 # f.close()
10 
11 
12 
13 
14 # import os
15 # with open('old.txt','r',encoding='utf-8') as read_f,\
16 #     open('.old.txt.swap','w',encoding='utf-8') as write_f:
17 #     msg=read_f.read()
18 #     # print(msg,type(msg))
19 #     msg=msg.replace('alex','SB')
20 #     # print(msg)
21 #     write_f.write(msg)
22 #
23 # os.remove('old.txt')
24 # os.rename('.old.txt.swap','old.txt')
25 
26 
27 
28 
29 import os
30 with open('old.txt','r',encoding='utf-8') as read_f,\
31     open('.old.txt.swap','w',encoding='utf-8') as write_f:
32     for line in read_f:
33         if 'SB' in line:
34             line=line.replace('SB','alex')
35         write_f.write(line)
36 os.remove('old.txt')
37 os.rename('.old.txt.swap','old.txt')
文件处理
  1 # pythons=['alex','egon','yuanhao','wupeiqi','gangdan','biubiu']
  2 # linuxs=['wupeiqi','oldboy','gangdan']
  3 #
  4 # res=[]
  5 # for p in pythons:
  6 #     if p in linuxs:
  7 #         res.append(p)
  8 #
  9 # print(res)
 10 #关系运算???
 11 
 12 
 13 #1 集合内可以有多个元素,但是每个元素都必须是不可变类型,即可hash类型
 14 #2 集合内的元素唯一
 15 #3 集合是无序的
 16 # s={1,'a',1,1,1,1,1,1} #s=set({1,'a',1,1,1,1,1,1})
 17 
 18 
 19 # s1=set('hello')
 20 # print(s1,type(s1))
 21 # s={'a',3,9,'b'}
 22 # print(s)
 23 
 24 #集合优先掌握的方法
 25 # pythons={'alex','egon','yuanhao','wupeiqi','gangdan','biubiu'}
 26 
 27 # print('alex' not in pythons)
 28 # print(pythons)
 29 
 30 #关系运算
 31 # s1={1,10,11,22}
 32 # s2={1,11,33}
 33 
 34 #交集
 35 # print(s1 & s2)
 36 
 37 #并集
 38 # print(s1 | s2)
 39 
 40 #差集
 41 # print(s1 - s2)
 42 # print(s2 - s1)
 43 
 44 #对称差集
 45 # print(s1 ^ s2)
 46 
 47 
 48 
 49 #父集
 50 # s1={1,2,3,4}
 51 # s2={1,5}
 52 # print(s1 >= s2)
 53 #
 54 # #子集
 55 # print(s1 <= s2)
 56 # print(s2 <= s1)
 57 
 58 
 59 #集合练习一
 60 
 61 # pythons={'alex','egon','yuanhao','wupeiqi','gangdan','biubiu'}
 62 # linuxs={'wupeiqi','oldboy','gangdan'}
 63 #
 64 #
 65 # # 1. 求出即报名python又报名linux课程的学员名字集合
 66 # print(pythons & linuxs)
 67 # #   2. 求出所有报名的学生名字集合
 68 # print(pythons | linuxs)
 69 # #   3. 求出只报名python课程的学员名字
 70 # print(pythons - linuxs)
 71 # #   4. 求出没有同时这两门课程的学员名字集合
 72 # print(pythons ^ linuxs)
 73 
 74 
 75 
 76 #集合练习二:
 77 #  1. 有列表l=['a','b',1,'a','a'],列表元素均为可hash类型,去重,得到新列表,且新列表无需保持列表原来的顺序
 78 # l=['a','b',1,'a','a']
 79 #
 80 # s=set(l)
 81 # print(s)
 82 # print(list(s)
 83 # )
 84 
 85 
 86 #    2.在上题的基础上,保存列表原来的顺序
 87 # l=['a','b',1,'a','a']
 88 #
 89 # l1=[]
 90 # for item in l:
 91 #     if item not in l1:
 92 #         l1.append(item)
 93 # print(l1)
 94 #
 95 # l1=[]
 96 # s=set()
 97 # for item in l:
 98 #     if item not in s:
 99 #         s.add(item) #{'a','b',1}
100 #         # l1.append(item)
101 #         l1.append(item)
102 #
103 # print(l1)
104 
105 #   
106 #    4.有如下列表,列表元素为不可hash类型,去重,得到新列表,且新列表一定要保持列表原来的顺序
107 #
108 # l=[
109 #     {'name':'egon','age':18,'sex':'male'},
110 #     {'name':'alex','age':73,'sex':'male'},
111 #     {'name':'egon','age':20,'sex':'female'},
112 #     {'name':'egon','age':18,'sex':'male'},
113 #     {'name':'egon','age':18,'sex':'male'},
114 # ]
115 #
116 # l1=[]
117 # for item in l:
118 #     if item not in l1:
119 #         l1.append(item)
120 # print(l1)
121 
122 
123 
124 
125 # l1=[]
126 # s=set()
127 # for item in l:
128 #     val=(item['name'],item['age'],item['sex'])
129 #     # print(val)
130 #     if val not in s:
131 #         s.add(val)
132 #         # print(val)
133 #         l1.append(item)
134 #
135 # print(l1)
136 
137 
138 
139 
140 
141 #集合的内置方法
142 pythons={'alex','egon','yuanhao','wupeiqi','gangdan','biubiu'}
143 linuxs={'wupeiqi','oldboy','gangdan'}
144 # 1. 求出即报名python又报名linux课程的学员名字集合
145 # print(pythons & linuxs)
146 # print(pythons.intersection(linuxs))
147 
148 #   2. 求出所有报名的学生名字集合
149 # print(pythons | linuxs)
150 # print(pythons.union(linuxs))
151 #   3. 求出只报名python课程的学员名字
152 # print(pythons - linuxs)
153 # print(pythons.difference(linuxs))
154 #   4. 求出没有同时这两门课程的学员名字集合
155 # print(pythons ^ linuxs)
156 # print(pythons.symmetric_difference(linuxs))
157 
158 s={1,2,3,'a'}
159 # s.add(4)
160 # print(s)
161 
162 # print(s.pop())
163 
164 # s.remove('a')
165 # print(s)
166 
167 # s.remove('vvvvvvvvvv')
168 # s.discard('aaaaaa')
169 # print(s)
集合
  1 my_girl_friends=['alex','wupeiqi','yuanhao',4,10,30]
  2 # my_girl_friends=list(['alex','wupeiqi','yuanhao',4,10,30])
  3 
  4 
  5 # print(type(my_girl_friends))
  6 
  7 # print(my_girl_friends[2])
  8 #
  9 # print(my_girl_friends[1:3])
 10 
 11 # my_girl_friends.append('oldboy')
 12 # print(my_girl_friends)
 13 
 14 #pop按照索引
 15 # my_girl_friends.pop()
 16 # my_girl_friends.pop()
 17 # my_girl_friends.pop(0)
 18 # my_girl_friends.pop(0)
 19 # my_girl_friends.pop(1)
 20 
 21 #remove按照值
 22 # my_girl_friends.remove('yuanhao')
 23 # print(my_girl_friends)
 24 
 25 
 26 # my_girl_friends.__len__()
 27 # print(len(my_girl_friends))
 28 
 29 # print('wupeiqi' in my_girl_friends)
 30 #
 31 # msg='my name is egon111111'
 32 # print('egon' in msg)
 33 
 34 #其他操作(掌握)
 35 # my_girl_friends=['alex','wupeiqi','alex','yuanhao',4,10,30]
 36 # my_girl_friends.insert(1,'Sb')
 37 # print(my_girl_friends)
 38 
 39 
 40 
 41 
 42 #其他操作(了解)
 43 my_girl_friends=['alex','wupeiqi','alex','yuanhao',4,10,30]
 44 # my_girl_friends.clear()
 45 # print(my_girl_friends)
 46 
 47 # l=my_girl_friends.copy()
 48 # print(l)
 49 
 50 # print(my_girl_friends.count('alex'))
 51 
 52 # my_girl_friends.append('oldboy1')
 53 # my_girl_friends.append('oldboy2')
 54 # my_girl_friends.append('oldboy3')
 55 # print(my_girl_friends)
 56 # my_girl_friends.extend(['oldboy1','oldboy2','oldboy3'])
 57 # print(my_girl_friends)
 58 
 59 # print(my_girl_friends.index('alex'))
 60 # my_girl_friends.reverse()
 61 # print(my_girl_friends)
 62 
 63 # l=[3,-1,5,2]
 64 # l.sort(reverse=True)
 65 # print(l)
 66 
 67 
 68 
 69 #练习一:
 70 data=['alex',84,[1900,3,38]]
 71 # print(data[0])
 72 # print(data[1])
 73 # print(data[2][0])
 74 
 75 
 76 # name,age,birth=data
 77 # print(name)
 78 # print(age)
 79 # print(birth)
 80 #
 81 #
 82 # msg='hello'
 83 # a,b,c,d,e=msg
 84 # print(a,b,c,d,e)
 85 
 86 
 87 # msg='hello'
 88 # a,_,_,_,b=msg
 89 # print(a)
 90 # print(b)
 91 
 92 # a,*_,b=msg
 93 # print(a,b)
 94 
 95 
 96 #队列:先进先出
 97 fifo=[]
 98 #入队
 99 # fifo.append('first')
100 # fifo.append('second')
101 # fifo.append('third')
102 # print(fifo)
103 # #出队
104 # print(fifo.pop(0))
105 # print(fifo.pop(0))
106 # print(fifo.pop(0))
107 
108 #入队
109 # fifo.insert(0,'first')
110 # fifo.insert(0,'second')
111 # fifo.insert(0,'third')
112 # print(fifo)
113 #
114 # #出队
115 # print(fifo.pop())
116 # print(fifo.pop())
117 # print(fifo.pop())
118 
119 
120 
121 #堆栈:先进后出
122 lifo=[]
集合
 1 按存值个数区分
 2     标量/原子类型:数字,字符串
 3     容器类型:列表,元组,字典
 4 
 5 按可变不可变区分
 6     可变:列表,字典
 7     不可变:数字,字符串,元组
 8 
 9 按访问方式区分
10     直接访问:数字
11     按照索引访问(序列类型):字符串,列表,元组
12     key访问(映射类型)    字典
数字类型总结
 1 age=(11,22,33,44,55,33)# 本质age=tuple((11,22,33,44,55))
 2 
 3 # print(age[2])
 4 # print(age[1:4])
 5 # print(len(age))
 6 #
 7 # print(11 in age)
 8 
 9 
10 # print(age.index(33))
11 # print(age.count(33))
12 
13 
14 #元组练习
15 msg_dic={
16 'apple':10,
17 'tesla':100000,
18 'mac':3000,
19 'lenovo':30000,
20 'chicken':10,
21 }
22 goods_l=[]
23 
24 while True:
25     for key in msg_dic:
26         # print('Goods Name:%s Price:%s' %(key,msg_dic[key]))
27         print('\033[43mName:{name} Price:{price}\033[0m'.format(price=msg_dic[key],name=key))
28     choice=input('your goods name>>: ').strip()
29     if len(choice) == 0 or choice not in msg_dic:continue
30     count=input('your count>>: ').strip()
31     if count.isdigit():
32         goods_l.append((choice,msg_dic[choice],int(count)))
33     print(goods_l)
元组
  1 info={'name':'egon','age':18,'sex':'male'}
  2 #本质info=dict({'name':'egon','age':18,'sex':'male'})
  3 
  4 
  5 # print(info['age'])
  6 # info['height']=1.80
  7 #
  8 # print(info)
  9 #
 10 # for key in info:
 11 #     print(key)
 12 
 13 
 14 #字典的key必须是不可变类型,也成为可hash类型
 15 # info={(1,2):'a'}
 16 # print(info[(1,2)])
 17 
 18 #字典常用的方法(优先掌握)
 19 info={'name':'egon','age':18,'sex':'male'}
 20 # print(info.pop('name'))
 21 # print(info)
 22 # print(info.pop('asdfsadfasdfasfasdfasdfasdf',None))
 23 
 24 
 25 # print(info['name1'])
 26 # print(info.get('name1'))
 27 # print(info.get('nameasdfasdfasdfasdf','not key'))
 28 
 29 
 30 #字典其他的方法
 31 info={'name':'egon','age':18,'sex':'male'}
 32 # print(info.popitem())
 33 # print(info.popitem())
 34 # print(info)
 35 #
 36 # print(info.keys(),type(info.keys()))
 37 # print(info.values())
 38 
 39 # for key in info.keys():
 40 #     print(key)
 41 
 42 # for key in info.values():
 43 #     print(key)
 44 
 45 # for key in info:
 46 #     print(key,info[key])
 47 
 48 # print(info.items())
 49 # for key,value in info.items(): # key,value=('name','egon')
 50 #     print(key,value)
 51 
 52 
 53 # msg_dic={
 54 # 'apple':10,
 55 # 'tesla':100000,
 56 # 'mac':3000,
 57 # 'lenovo':30000,
 58 # 'chicken':10,
 59 # }
 60 # for key,value in msg_dic.items():
 61 #     print(key,value)
 62 
 63 
 64 # info={'name':'egon','age':18,'sex':'male'}
 65 # info.clear()
 66 # print(info)
 67 
 68 # print(info.items())
 69 # dic=info.fromkeys(['name','age','sex'],11111111)
 70 # print(dic)
 71 #
 72 # dic=info.fromkeys(['name','age','sex'],None)
 73 # print(dic)
 74 
 75 #
 76 # dic=dict(a=1,b=2,c=3)
 77 # print(dic)
 78 
 79 # print(info.items())
 80 
 81 # print(dict([('name', 'egon'), ('age', 18), ('sex', 'male')]))
 82 
 83 
 84 # dic=dict.fromkeys(['name','age','sex'],11111111)
 85 # print(dic)
 86 # print(info)
 87 
 88 
 89 
 90 
 91 
 92 # print(info)
 93 # dic={'a':1,'b':2,'name':'SHUAI'}
 94 # info.update(dic)
 95 # print(info)
 96 
 97 
 98 # d=dict.setdefault(['a','b','c'],[])
 99 # print(d)
100 #
101 # d={}
102 # print(d)
103 # d['name']='egon'
104 # d['age']=18
105 # d['sex']='male'
106 # # d['hobby']=[]
107 # # d['hobby'].append('play basketball')
108 # # d['hobby'].append('play football')
109 #
110 # d.setdefault('hobby',[]).append('play1') #d['hobby']
111 # d.setdefault('hobby',[]).append('play2') #d['hobby']
112 # d.setdefault('hobby',[]).append('play3') #d['hobby']
113 # print(d)
114 
115 
116 #字典练习
117 # nums=[11, 22, 33, 44, 55, 66, 77, 88, 99, 90]
118 # dic={
119 #     'k1':[],
120 #     'k2':[],
121 # }
122 # for item in nums:
123 #     if item >= 66:
124 #         dic['k1'].append(item)
125 #     else:
126 #         dic['k2'].append(item)
127 #
128 # print(dic)
129 
130 
131 
132 
133 
134 
135 
136 
137 s='hello alex alex say hello sb sb'
138 words=s.split()
139 # print(words)
140 dic={}
141 for word in words:
142     # print(word)
143     if word not in dic:
144         dic[word]=1
145         #{'hello':1,'alex':1}
146     else:
147         dic[word]+=1
148 
149 print(dic)
字典
  1 # name='egon' #name=str('egon')
  2 # name=str('egon')
  3 # print(type(name))
  4 # print(name)
  5 
  6 #优先掌握
  7 #索引
  8 # name='egon' #name=str('egon')
  9 # print(name[0])
 10 # print(name[1000])
 11 
 12 
 13 #移除空白
 14 # name=input('username: ')
 15 # # print(name)
 16 #
 17 # name=name.strip()
 18 # print(name)
 19 
 20 
 21 # name=input('username: ').strip()
 22 # print(name)
 23 
 24 
 25 # name=input('username: ')
 26 # print(name.strip())
 27 
 28 
 29 # name='***egon********'
 30 # # print(name.strip('*'))
 31 #
 32 # print(name.lstrip('*'))
 33 # print(name.rstrip('*'))
 34 
 35 
 36 #切分
 37 # user_info='root:x:0:0::/root:/bin/bash'
 38 # print(user_info.split(':')[5])
 39 
 40 # cmd_info='get|a.txt|333333333'
 41 # # print(cmd_info.split('|')[0])
 42 # print(cmd_info.split('|',1)[0])
 43 
 44 # msg='name         egon age 18'
 45 # print(msg.split())
 46 
 47 
 48 #取长度
 49 # name='egon'
 50 # # print(name.__len__())
 51 # print(len(name)) #name.__len__()
 52 
 53 
 54 #切出子字符串
 55 # name='hello world'
 56 # # print(name[1])
 57 # # print(name[2])
 58 # # print(name[3])
 59 # print(name[1:7:2])
 60 
 61 
 62 
 63 #字符的其他方法(掌握)
 64 # name='alex_SB'
 65 # print(name.endswith('SB'))
 66 # print(name.startswith('alex'))
 67 
 68 # name='alex say :i have one tesla,my name is alex'
 69 # print(name.replace('alex','SB',1))
 70 
 71 
 72 # print('{} {} {}'.format('egon',18,'male'))
 73 # print('{0} {1} {0}'.format('egon',18,'male'))
 74 # print('NAME:{name} AGE:{age} SEX:{sex}'.format(age=18,sex='male',name='egon'))
 75 
 76 # num='123'
 77 # print(num.isdigit())
 78 
 79 # oldboy_age=73
 80 # while True:
 81 #     age=input('>>: ').strip()
 82 #     if len(age) == 0:continue
 83 #     if age.isdigit():
 84 #         age=int(age)
 85 #         print(age,type(age))
 86 
 87 
 88 
 89 
 90 
 91 
 92 #字符其他需要了解的方法
 93 
 94 name='egon hello'
 95 # print(name.find('o'))
 96 # print(name.find('x'))
 97 # print(name.find('o',3,6))
 98 
 99 # print(name.index('o'))
100 # print(name.index('x'))
101 
102 
103 # print(name.count('o',1,3))
104 #
105 # l=['egon','say','hello','world'] #类别内容必须都是字符串
106 # print(':'.join(l))
107 
108 # name='egon'
109 # print(name.center(30,'*'))
110 # print(name.ljust(30,'*'))
111 # print(name.rjust(30,'*'))
112 # print(name.zfill(30))
113 
114 
115 
116 # name='egon\thello'
117 # print(name)
118 # print(name.expandtabs(1))
119 
120 # name='EGON'
121 # print(name.lower())
122 #
123 # name='eg'
124 # print(name.upper())
125 
126 
127 # name='egon say'
128 #
129 # print(name.capitalize()) #首字母大写
130 # print(name.swapcase()) #大小写翻转
131 # msg='egon say hi'
132 # print(msg.title()) #每个单词的首字母大写
133 
134 # name='egon123'
135 # print(name.isalnum()) #字符串由字母和数字组成
136 # name='egon'
137 # print(name.isalpha()) #字符串只由字母组成
138 
139 
140 
141 num1=b'4' #Bytes
142 num2=u'4' #unicode,python3中无需加u就是unicode
143 num3='' #中文数字
144 num4='' #罗马数字
145 
146 #bytes,unicode
147 # print(num1.isdigit())
148 # print(num2.isdigit())
149 # print(num3.isdigit())
150 # print(num4.isdigit())
151 
152 
153 #isdecimal:unicode
154 # print(num2.isdecimal())
155 # print(num3.isdecimal())
156 # print(num4.isdecimal())
157 
158 
159 #isnumberic:unicode,汉字,罗马
160 # print(num2.isnumeric())
161 # print(num3.isnumeric())
162 # print(num4.isnumeric())
字符串
原文地址:https://www.cnblogs.com/ikere/p/7154781.html