Python之经常使用模块（待更新）

时间 2019-12-07

原文原文链接

模块，用一砣代码实现了某个功能的代码集合。 html

相似于函数式编程和面向过程编程，函数式编程则完成一个功能，其余代码用来调用便可，提供了代码的重用性和代码间的耦合。而对于一个复杂的功能来，可能须要多个函数才能完成（函数又能够在不一样的.py文件中），n个 .py 文件组成的代码集合就称为模块。node

如：os 是系统相关的模块；file是文件操做相关的模块python

模块分为三种：git

自定义模块
内置模块
开源模块

自定义模块

一、定义模块程序员

情景一：github

情景二：web

情景三：算法

二、导入模块shell

Python之因此应用愈来愈普遍，在必定程度上也依赖于其为程序员提供了大量的模块以供使用，若是想要使用模块，则须要导入。导入模块有一下几种方法：编程

 
         import  
         module 
        
         from  
         module.xx.xx  
         import  
         xx 
        
         from  
         module.xx.xx  
         import  
         xx as rename  
        
         from  
         module.xx.xx  
         import  
         *

导入模块其实就是告诉Python解释器去解释那个py文件

导入一个py文件，解释器解释该py文件
导入一个包，解释器解释该包下的 __init__.py 文件

开源模块

1、下载安装

下载安装有两种方式：

 
  yum 
pip
apt-get
... 
 

 
  下载源码
解压源码
进入目录
编译源码    python setup.py build
安装源码    python setup.py install 
 

注：在使用源码安装时，须要使用到gcc编译和python开发环境，因此，须要先执行：

 
         yum install gcc 
        
         yum install python 
         - 
         devel 
        
         或 
        
         apt 
         - 
         get python 
         - 
         dev

安装成功后，模块会自动安装到 sys.path 中的某个目录中，如：

2、导入模块

同自定义模块中导入的方式

3、模块 paramiko

paramiko是一个用于作远程控制的模块，使用该模块能够对远程服务器进行命令或文件操做，值得一说的是，fabric和ansible内部的远程管理就是使用的paramiko来现实。

一、下载安装

 
         # pycrypto，因为 paramiko 模块内部依赖pycrypto，因此先下载安装pycrypto 
        
         # 下载安装 pycrypto 
        
         wget http: 
         / 
         / 
         files.cnblogs.com 
         / 
         files 
         / 
         wupeiqi 
         / 
         pycrypto 
         - 
         2.6 
         . 
         1.tar 
         .gz 
        
         tar  
         - 
         xvf pycrypto 
         - 
         2.6 
         . 
         1.tar 
         .gz 
        
         cd pycrypto 
         - 
         2.6 
         . 
         1 
        
         python setup.py build 
        
         python setup.py install 
        
         # 进入python环境，导入Crypto检查是否安装成功 
        
         # 下载安装 paramiko 
        
         wget http: 
         / 
         / 
         files.cnblogs.com 
         / 
         files 
         / 
         wupeiqi 
         / 
         paramiko 
         - 
         1.10 
         . 
         1.tar 
         .gz 
        
         tar  
         - 
         xvf paramiko 
         - 
         1.10 
         . 
         1.tar 
         .gz 
        
         cd paramiko 
         - 
         1.10 
         . 
         1 
        
         python setup.py build 
        
         python setup.py install 
        
         # 进入python环境，导入paramiko检查是否安装成功

二、使用模块

 
#!/usr/bin/env python
#coding:utf-8

import paramiko

ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('192.168.1.108', 22, 'alex', '123')
stdin, stdout, stderr = ssh.exec_command('df')
print stdout.read()
ssh.close();

 
import paramiko

private_key_path = '/home/auto/.ssh/id_rsa'
key = paramiko.RSAKey.from_private_key_file(private_key_path)

ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('主机名 ', 端口, '用户名', key)

stdin, stdout, stderr = ssh.exec_command('df')
print stdout.read()
ssh.close()

 
    
  
import os,sys
import paramiko

t = paramiko.Transport(('182.92.219.86',22))
t.connect(username='wupeiqi',password='123')
sftp = paramiko.SFTPClient.from_transport(t)
sftp.put('/tmp/test.py','/tmp/test.py') 
t.close()


import os,sys
import paramiko

t = paramiko.Transport(('182.92.219.86',22))
t.connect(username='wupeiqi',password='123')
sftp = paramiko.SFTPClient.from_transport(t)
sftp.get('/tmp/test.py','/tmp/test2.py')
t.close() 
    
  

 
import paramiko

pravie_key_path = '/home/auto/.ssh/id_rsa'
key = paramiko.RSAKey.from_private_key_file(pravie_key_path)

t = paramiko.Transport(('182.92.219.86',22))
t.connect(username='wupeiqi',pkey=key)

sftp = paramiko.SFTPClient.from_transport(t)
sftp.put('/tmp/test3.py','/tmp/test3.py') 

t.close()

import paramiko

pravie_key_path = '/home/auto/.ssh/id_rsa'
key = paramiko.RSAKey.from_private_key_file(pravie_key_path)

t = paramiko.Transport(('182.92.219.86',22))
t.connect(username='wupeiqi',pkey=key)

sftp = paramiko.SFTPClient.from_transport(t)
sftp.get('/tmp/test3.py','/tmp/test4.py') 

t.close()

内置模块

time & datetime模块

 
    
     
       
       
         import  
         time 
        
 
         import  
         datetime 
        

            
        
 
         time 
        
 
         print 
         (time.clock())   
         #返回处理器时间，3.3之后废弃 4.444098792316153e-07 
        
 
         print 
         (time.process_time())  
         #返回处理器时间 0.031200199999999997 
        
 
         print 
         (time.time())      
         #返回当前系统时间戳 1463472071.3892002 
        
 
         print 
         (time.ctime())     
         #返回当前系统时间 Tue May 17 16:01:11 2016 
        
 
         print 
         (time.ctime(time.time() 
         - 
         86400 
         ))    
         #转换成字符串格式 Mon May 16 16:01:11 2016 
        
 
         print 
         (time.gmtime(time.time() 
         - 
         86400 
         ))   
         #将时间戳转换成struct_time格式 time.struct_time(tm_year=2016, tm_mon=5, tm_mday=16, tm_hour=8, tm_min=1, tm_sec=11, tm_wday=0, tm_yday=137, tm_isdst=0) 
        
 
         print 
         (time.localtime(time.time() 
         - 
         86400 
         ))   
         #将时间戳转换成struct_time格式,本地时间。 time.struct_time(tm_year=2016, tm_mon=5, tm_mday=16, tm_hour=16, tm_min=13, tm_sec=25, tm_wday=0, tm_yday=137, tm_isdst=0) 
        
 
         print 
         (time.mktime(time.localtime()))   
         #与time.localtime()功能相反,将struct_time格式转回成时间戳格式  1463472904.0 
        
 
         time.sleep( 
         4 
         )  
         #sleep 每隔四秒以执行 
        
 
         print 
         (time.strftime( 
         "%Y-%m-%d %H:%M:%S" 
         ,time.gmtime()) )  
         #将struct_time格式转成指定的字符串格式  2016-05-17 08:16:22 
        

            
        
 
         datetime 
        
 
         print 
         (datetime.date.today())  
         #输出格式 2016-05-17 
        
 
         print 
         (datetime.date.fromtimestamp(time.time() 
         - 
         86400 
         ) )  
         # 将时间戳转成日期格式 2016-05-16 
        
 
         current_time  
         =  
         datetime.datetime.now()  
         # 
        
 
         print 
         (current_time)  
         #输出2016-05-17 16:17:59.863200 
        
 
         print 
         (current_time.timetuple())  
         #返回struct_time格式  time.struct_time(tm_year=2016, tm_mon=5, tm_mday=17, tm_hour=16, tm_min=17, tm_sec=59, tm_wday=1, tm_yday=138, tm_isdst=-1) 
        

            
        
 
         #datetime.replace([year[, month[, day[, hour[, minute[, second[, microsecond[, tzinfo]]]]]]]]) 
        
 
         print 
         (current_time.replace( 
         2016 
         , 
         5 
         , 
         17 
         ))  
         #输出2016-05-17 16:19:33.753200,返回当前时间,但指定的值将被替换 
        

            
        
 
         str_to_date  
         =  
         datetime.datetime.strptime( 
         "21/11/06 16:30" 
         ,  
         "%d/%m/%y %H:%M" 
         )  
         #将字符串转换成日期格式 
        
 
         new_date1  
         =  
         datetime.datetime.now()  
         +  
         datetime.timedelta(days 
         = 
         10 
         )  
         #比如今加10天 2016-05-27 16:21:16.279200 
        
 
         new_date2  
         =  
         datetime.datetime.now()  
         +  
         datetime.timedelta(days 
         = 
         - 
         10 
         )  
         #比如今减10天 2016-05-07 16:21:44.459200 
        
 
         new_date3  
         =  
         datetime.datetime.now()  
         +  
         datetime.timedelta(hours 
         = 
         - 
         10 
         )  
         #比如今减10小时 2016-05-17 06:22:01.299200 
        
 
         new_date4  
         =  
         datetime.datetime.now()  
         +  
         datetime.timedelta(seconds 
         = 
         120 
         )  
         #比如今+120s 2016-05-17 16:24:10.917200 
        
 
         new_date5  
         =  
         datetime.datetime.now()  
         +  
         datetime.timedelta(weeks 
         = 
         20 
         )  
         #比如今+10周 2016-10-04 16:23:02.904200 
        
 
         print 
         (new_date5) 
        
 
     
 
    
  

Directive	Meaning	Notes
`%a`	Locale’s abbreviated weekday name.
`%A`	Locale’s full weekday name.
`%b`	Locale’s abbreviated month name.
`%B`	Locale’s full month name.
`%c`	Locale’s appropriate date and time representation.
`%d`	Day of the month as a decimal number [01,31].
`%H`	Hour (24-hour clock) as a decimal number [00,23].
`%I`	Hour (12-hour clock) as a decimal number [01,12].
`%j`	Day of the year as a decimal number [001,366].
`%m`	Month as a decimal number [01,12].
`%M`	Minute as a decimal number [00,59].
`%p`	Locale’s equivalent of either AM or PM.	(1)
`%S`	Second as a decimal number [00,61].	(2)
`%U`	Week number of the year (Sunday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Sunday are considered to be in week 0.	(3)
`%w`	Weekday as a decimal number [0(Sunday),6].
`%W`	Week number of the year (Monday as the first day of the week) as a decimal number [00,53]. All days in a new year preceding the first Monday are considered to be in week 0.	(3)
`%x`	Locale’s appropriate date representation.
`%X`	Locale’s appropriate time representation.
`%y`	Year without century as a decimal number [00,99].
`%Y`	Year with century as a decimal number.
`%z`	Time zone offset indicating a positive or negative time difference from UTC/GMT of the form +HHMM or -HHMM, where H represents decimal hour digits and M represents decimal minute digits [-23:59, +23:59].
`%Z`	Time zone name (no characters if no time zone exists).
`%%`	A literal `'%'` character.

random模块

随机数

 
         mport random 
        
         print  
         random.random() 
        
         print  
         random.randint( 
         1 
         , 
         2 
         ) 
        
         print  
         random.randrange( 
         1 
         , 
         10 
         )

生成随机验证码

 
    
     
       
       
         import   
         random 
        
 
         tmp  
         =  
         "" 
        
 
         for  
         i  
         in  
         range 
         ( 
         6 
         ): 
        
 
              
         rad1  
         =  
         random.randrange( 
         4 
         ) 
        
 
              
         if  
         rad1  
         = 
         = 
         1  
         or  
         rad1  
         = 
         = 
         3 
         : 
        
 
                  
         rad2  
         =  
         random.randrange( 
         0 
         , 
         9 
         ) 
        
 
                  
         tmp  
         + 
         =  
         str 
         (rad2) 
        
 
              
         else 
         : 
        
 
                  
         rad3  
         =  
         random.randrange( 
         65 
         , 
         90 
         ) 
        
 
                  
         tmp  
         + 
         =  
         chr 
         (rad3) 
        
 
         print 
         (tmp) 
        
 
     
 
    
  

sys模块

 
         import  
         sys 
        
         import  
         time 
        
         print 
         (sys.argv)     
         #['C:/Users/Administrator/PycharmProjects/zyl/day-6/datetime,time模块/SYS.PY.py'] 
        
         print 
         (sys.path)     
         #返回模块的搜索路径，初始化时使用PYTHONPATH环境变量的值 
        
         print 
         (exit())    
         #退出程序，正常退出时exit(0) 
        
         print 
         (sys.version)   
         #3.5.1 (v3.5.1:37a07cee5969, Dec  6 2015, 01:54:25) [MSC v.1900 64 bit (AMD64)] 
        
         print 
         (sys.maxsize)    
         #9223372036854775807  最大的Int值 
        
         print 
         (sys.platform)   
         #win32       操做系统类型 
        
         ####################################安装包流程不换行显示################################## 
        
         for   
         i  
         in  
         range 
         ( 
         31 
         ): 
        
         sys.stdout.write( 
         "\r" 
         )          
         #清空当前数据网上叠加 
        
         sys.stdout.write( 
         "%s%% | %s "  
         % 
         ( 
         int 
         (i 
         / 
         30 
         * 
         100 
         ), 
         int 
         (i 
         / 
         30 
         * 
         100 
         ) 
         * 
         "#" 
         )) 
        
         sys.stdout.flush() 
        
         time.sleep( 
         0.3 
         ) 
        
         ####################################安装流程换行显示#################################### 
        
         for  
         i  
         in  
         range 
         ( 
         101 
         ): 
        
         sys.stdout.write( 
         "\r" 
         ) 
        
         sys.stdout.write( 
         "%s%% | %s \n"  
         % 
         (i,i 
         * 
         "#" 
         )) 
        
         sys.stdout.flush() 
        
         time.sleep( 
         0.1 
         )

json & pickle 模块

用于序列化的两个模块

json，用于字符串和 python数据类型间进行转换
pickle，用于python特有的类型和 python的数据类型间进行转换

Json模块提供了四个功能：dumps、dump、loads、load

pickle模块提供了四个功能：dumps、dump、loads、load

 
    
  
import pickle

accounts = {
    1000: {
        'name':'Zhangyanlin',
        'email': '75501664@126.com',
        'passwd': 'abc123',
        'balance': 15000,
        'phone': 13651054608,
        'bank_acc':{
            'ICBC':14324234,
            'CBC' : 235234,
            'ABC' : 35235423
        }
    },
    1001: {
        'name': 'CaiXin Guo',
        'email': 'caixin@126.com',
        'passwd': 'abc145323',
        'balance': -15000,
        'phone': 1345635345,
        'bank_acc': {
            'ICBC': 4334343,
        }
    },
}

################################原始写入文件中去###############################
with open("zhang","wb") as f:
    f.write(pickle.dumps(accounts))               #打开文件将原数据保存到文件中


################################购物环节#######################################
with open("zhang","rb") as f:
   zhang_dic = pickle.loads(f.read())             #读取出文件里的内容赋值给zhang_dic变量

zhang_dic[1000]['balance'] -= 1000              #购物消费100，总价减去1000块钱


with open("zhang","wb") as f:
    f.write(pickle.dumps(zhang_dic))              #写入到数据中去

##############################刷新购物后文件里面的数据#########################

with open("zhang","rb") as f:
    shop_old = pickle.loads(f.read())          #把新数据更新到文件中去
print(shop_old) 
    
  

 
    
  
#json.loads(参数)将字符串转换成python识别的字符
li = '[11,22,33,44,55,66,77,88,99]'
dic = '{"sdkf":"123","askd":"123"}'
print(json.loads(li),type(json.loads(li)))    #列表类型
print(json.loads(dic),type(json.loads(dic)))  #字典类型

#json.dumps(参数)将python字符转换成其余语言识别的字符
li = [11,22,33,44,55]
dic = {"sdkf":"123","askd":"123"}
print(json.dumps(li),type(json.dumps(li)))        #转成字符串
print(json.dumps(dic),type(json.dumps(dic)))      #转成字符串 
    
  

collection系列

一、计数器（counter）

Counter是对字典类型的补充，用于追踪值的出现次数。

ps：具有字典的全部功能 + 本身的功能

 
    
     
       
       
         c  
         =  
         Counter( 
         'abcdeabcdabcaba' 
         ) 
        
 
         print  
         c 
        
 
         输出：Counter({ 
         'a' 
         :  
         5 
         ,  
         'b' 
         :  
         4 
         ,  
         'c' 
         :  
         3 
         ,  
         'd' 
         :  
         2 
         ,  
         'e' 
         :  
         1 
         }) 
        
 
     
 
    
  

 
    
  
########################################################################
###  Counter
########################################################################

class Counter(dict):
    '''Dict subclass for counting hashable items.  Sometimes called a bag
    or multiset.  Elements are stored as dictionary keys and their counts
    are stored as dictionary values.

    >>> c = Counter('abcdeabcdabcaba')  # count elements from a string

    >>> c.most_common(3)                # three most common elements
    [('a', 5), ('b', 4), ('c', 3)]
    >>> sorted(c)                       # list all unique elements
    ['a', 'b', 'c', 'd', 'e']
    >>> ''.join(sorted(c.elements()))   # list elements with repetitions
    'aaaaabbbbcccdde'
    >>> sum(c.values())                 # total of all counts

    >>> c['a']                          # count of letter 'a'
    >>> for elem in 'shazam':           # update counts from an iterable
    ...     c[elem] += 1                # by adding 1 to each element's count
    >>> c['a']                          # now there are seven 'a'
    >>> del c['b']                      # remove all 'b'
    >>> c['b']                          # now there are zero 'b'

    >>> d = Counter('simsalabim')       # make another counter
    >>> c.update(d)                     # add in the second counter
    >>> c['a']                          # now there are nine 'a'

    >>> c.clear()                       # empty the counter
    >>> c
    Counter()

    Note:  If a count is set to zero or reduced to zero, it will remain
    in the counter until the entry is deleted or the counter is cleared:

    >>> c = Counter('aaabbc')
    >>> c['b'] -= 2                     # reduce the count of 'b' by two
    >>> c.most_common()                 # 'b' is still in, but its count is zero
    [('a', 3), ('c', 1), ('b', 0)]

    '''
    # References:
    #   http://en.wikipedia.org/wiki/Multiset
    #   http://www.gnu.org/software/smalltalk/manual-base/html_node/Bag.html
    #   http://www.demo2s.com/Tutorial/Cpp/0380__set-multiset/Catalog0380__set-multiset.htm
    #   http://code.activestate.com/recipes/259174/
    #   Knuth, TAOCP Vol. II section 4.6.3

    def __init__(self, iterable=None, **kwds):
        '''Create a new, empty Counter object.  And if given, count elements
        from an input iterable.  Or, initialize the count from another mapping
        of elements to their counts.

        >>> c = Counter()                           # a new, empty counter
        >>> c = Counter('gallahad')                 # a new counter from an iterable
        >>> c = Counter({'a': 4, 'b': 2})           # a new counter from a mapping
        >>> c = Counter(a=4, b=2)                   # a new counter from keyword args

        '''
        super(Counter, self).__init__()
        self.update(iterable, **kwds)

    def __missing__(self, key):
        """ 对于不存在的元素，返回计数器为0 """
        'The count of elements not in the Counter is zero.'
        # Needed so that self[missing_item] does not raise KeyError
        return 0

    def most_common(self, n=None):
        """ 数量大于等n的全部元素和计数器 """
        '''List the n most common elements and their counts from the most
        common to the least.  If n is None, then list all element counts.

        >>> Counter('abcdeabcdabcaba').most_common(3)
        [('a', 5), ('b', 4), ('c', 3)]

        '''
        # Emulate Bag.sortedByCount from Smalltalk
        if n is None:
            return sorted(self.iteritems(), key=_itemgetter(1), reverse=True)
        return _heapq.nlargest(n, self.iteritems(), key=_itemgetter(1))

    def elements(self):
        """ 计数器中的全部元素，注：此处非全部元素集合，而是包含全部元素集合的迭代器 """
        '''Iterator over elements repeating each as many times as its count.

        >>> c = Counter('ABCABC')
        >>> sorted(c.elements())
        ['A', 'A', 'B', 'B', 'C', 'C']

        # Knuth's example for prime factors of 1836:  2**2 * 3**3 * 17**1
        >>> prime_factors = Counter({2: 2, 3: 3, 17: 1})
        >>> product = 1
        >>> for factor in prime_factors.elements():     # loop over factors
        ...     product *= factor                       # and multiply them
        >>> product

        Note, if an element's count has been set to zero or is a negative
        number, elements() will ignore it.

        '''
        # Emulate Bag.do from Smalltalk and Multiset.begin from C++.
        return _chain.from_iterable(_starmap(_repeat, self.iteritems()))

    # Override dict methods where necessary

    @classmethod
    def fromkeys(cls, iterable, v=None):
        # There is no equivalent method for counters because setting v=1
        # means that no element can have a count greater than one.
        raise NotImplementedError(
            'Counter.fromkeys() is undefined.  Use Counter(iterable) instead.')

    def update(self, iterable=None, **kwds):
        """ 更新计数器，其实就是增长；若是原来没有，则新建，若是有则加一 """
        '''Like dict.update() but add counts instead of replacing them.

        Source can be an iterable, a dictionary, or another Counter instance.

        >>> c = Counter('which')
        >>> c.update('witch')           # add elements from another iterable
        >>> d = Counter('watch')
        >>> c.update(d)                 # add elements from another counter
        >>> c['h']                      # four 'h' in which, witch, and watch

        '''
        # The regular dict.update() operation makes no sense here because the
        # replace behavior results in the some of original untouched counts
        # being mixed-in with all of the other counts for a mismash that
        # doesn't have a straight-forward interpretation in most counting
        # contexts.  Instead, we implement straight-addition.  Both the inputs
        # and outputs are allowed to contain zero and negative counts.

        if iterable is not None:
            if isinstance(iterable, Mapping):
                if self:
                    self_get = self.get
                    for elem, count in iterable.iteritems():
                        self[elem] = self_get(elem, 0) + count
                else:
                    super(Counter, self).update(iterable) # fast path when counter is empty
            else:
                self_get = self.get
                for elem in iterable:
                    self[elem] = self_get(elem, 0) + 1
        if kwds:
            self.update(kwds)

    def subtract(self, iterable=None, **kwds):
        """ 相减，原来的计数器中的每个元素的数量减去后添加的元素的数量 """
        '''Like dict.update() but subtracts counts instead of replacing them.
        Counts can be reduced below zero.  Both the inputs and outputs are
        allowed to contain zero and negative counts.

        Source can be an iterable, a dictionary, or another Counter instance.

        >>> c = Counter('which')
        >>> c.subtract('witch')             # subtract elements from another iterable
        >>> c.subtract(Counter('watch'))    # subtract elements from another counter
        >>> c['h']                          # 2 in which, minus 1 in witch, minus 1 in watch
        >>> c['w']                          # 1 in which, minus 1 in witch, minus 1 in watch
        -1

        '''
        if iterable is not None:
            self_get = self.get
            if isinstance(iterable, Mapping):
                for elem, count in iterable.items():
                    self[elem] = self_get(elem, 0) - count
            else:
                for elem in iterable:
                    self[elem] = self_get(elem, 0) - 1
        if kwds:
            self.subtract(kwds)

    def copy(self):
        """ 拷贝 """
        'Return a shallow copy.'
        return self.__class__(self)

    def __reduce__(self):
        """ 返回一个元组（类型，元组） """
        return self.__class__, (dict(self),)

    def __delitem__(self, elem):
        """ 删除元素 """
        'Like dict.__delitem__() but does not raise KeyError for missing values.'
        if elem in self:
            super(Counter, self).__delitem__(elem)

    def __repr__(self):
        if not self:
            return '%s()' % self.__class__.__name__
        items = ', '.join(map('%r: %r'.__mod__, self.most_common()))
        return '%s({%s})' % (self.__class__.__name__, items)

    # Multiset-style mathematical operations discussed in:
    #       Knuth TAOCP Volume II section 4.6.3 exercise 19
    #       and at http://en.wikipedia.org/wiki/Multiset
    #
    # Outputs guaranteed to only include positive counts.
    #
    # To strip negative and zero counts, add-in an empty counter:
    #       c += Counter()

    def __add__(self, other):
        '''Add counts from two counters.

        >>> Counter('abbb') + Counter('bcc')
        Counter({'b': 4, 'c': 2, 'a': 1})

        '''
        if not isinstance(other, Counter):
            return NotImplemented
        result = Counter()
        for elem, count in self.items():
            newcount = count + other[elem]
            if newcount > 0:
                result[elem] = newcount
        for elem, count in other.items():
            if elem not in self and count > 0:
                result[elem] = count
        return result

    def __sub__(self, other):
        ''' Subtract count, but keep only results with positive counts.

        >>> Counter('abbbc') - Counter('bccd')
        Counter({'b': 2, 'a': 1})

        '''
        if not isinstance(other, Counter):
            return NotImplemented
        result = Counter()
        for elem, count in self.items():
            newcount = count - other[elem]
            if newcount > 0:
                result[elem] = newcount
        for elem, count in other.items():
            if elem not in self and count < 0:
                result[elem] = 0 - count
        return result

    def __or__(self, other):
        '''Union is the maximum of value in either of the input counters.

        >>> Counter('abbb') | Counter('bcc')
        Counter({'b': 3, 'c': 2, 'a': 1})

        '''
        if not isinstance(other, Counter):
            return NotImplemented
        result = Counter()
        for elem, count in self.items():
            other_count = other[elem]
            newcount = other_count if count < other_count else count
            if newcount > 0:
                result[elem] = newcount
        for elem, count in other.items():
            if elem not in self and count > 0:
                result[elem] = count
        return result

    def __and__(self, other):
        ''' Intersection is the minimum of corresponding counts.

        >>> Counter('abbb') & Counter('bcc')
        Counter({'b': 1})

        '''
        if not isinstance(other, Counter):
            return NotImplemented
        result = Counter()
        for elem, count in self.items():
            other_count = other[elem]
            newcount = count if count < other_count else other_count
            if newcount > 0:
                result[elem] = newcount
        return result

Counter 
    
  

二、有序字典(orderedDict )

orderdDict是对字典类型的补充，他记住了字典元素添加的顺序

 
    
  
class OrderedDict(dict):
    'Dictionary that remembers insertion order'
    # An inherited dict maps keys to values.
    # The inherited dict provides __getitem__, __len__, __contains__, and get.
    # The remaining methods are order-aware.
    # Big-O running times for all methods are the same as regular dictionaries.

    # The internal self.__map dict maps keys to links in a doubly linked list.
    # The circular doubly linked list starts and ends with a sentinel element.
    # The sentinel element never gets deleted (this simplifies the algorithm).
    # Each link is stored as a list of length three:  [PREV, NEXT, KEY].

    def __init__(self, *args, **kwds):
        '''Initialize an ordered dictionary.  The signature is the same as
        regular dictionaries, but keyword arguments are not recommended because
        their insertion order is arbitrary.

        '''
        if len(args) > 1:
            raise TypeError('expected at most 1 arguments, got %d' % len(args))
        try:
            self.__root
        except AttributeError:
            self.__root = root = []                     # sentinel node
            root[:] = [root, root, None]
            self.__map = {}
        self.__update(*args, **kwds)

    def __setitem__(self, key, value, dict_setitem=dict.__setitem__):
        'od.__setitem__(i, y) <==> od[i]=y'
        # Setting a new item creates a new link at the end of the linked list,
        # and the inherited dictionary is updated with the new key/value pair.
        if key not in self:
            root = self.__root
            last = root[0]
            last[1] = root[0] = self.__map[key] = [last, root, key]
        return dict_setitem(self, key, value)

    def __delitem__(self, key, dict_delitem=dict.__delitem__):
        'od.__delitem__(y) <==> del od[y]'
        # Deleting an existing item uses self.__map to find the link which gets
        # removed by updating the links in the predecessor and successor nodes.
        dict_delitem(self, key)
        link_prev, link_next, _ = self.__map.pop(key)
        link_prev[1] = link_next                        # update link_prev[NEXT]
        link_next[0] = link_prev                        # update link_next[PREV]

    def __iter__(self):
        'od.__iter__() <==> iter(od)'
        # Traverse the linked list in order.
        root = self.__root
        curr = root[1]                                  # start at the first node
        while curr is not root:
            yield curr[2]                               # yield the curr[KEY]
            curr = curr[1]                              # move to next node

    def __reversed__(self):
        'od.__reversed__() <==> reversed(od)'
        # Traverse the linked list in reverse order.
        root = self.__root
        curr = root[0]                                  # start at the last node
        while curr is not root:
            yield curr[2]                               # yield the curr[KEY]
            curr = curr[0]                              # move to previous node

    def clear(self):
        'od.clear() -> None.  Remove all items from od.'
        root = self.__root
        root[:] = [root, root, None]
        self.__map.clear()
        dict.clear(self)

    # -- the following methods do not depend on the internal structure --

    def keys(self):
        'od.keys() -> list of keys in od'
        return list(self)

    def values(self):
        'od.values() -> list of values in od'
        return [self[key] for key in self]

    def items(self):
        'od.items() -> list of (key, value) pairs in od'
        return [(key, self[key]) for key in self]

    def iterkeys(self):
        'od.iterkeys() -> an iterator over the keys in od'
        return iter(self)

    def itervalues(self):
        'od.itervalues -> an iterator over the values in od'
        for k in self:
            yield self[k]

    def iteritems(self):
        'od.iteritems -> an iterator over the (key, value) pairs in od'
        for k in self:
            yield (k, self[k])

    update = MutableMapping.update

    __update = update # let subclasses override update without breaking __init__

    __marker = object()

    def pop(self, key, default=__marker):
        '''od.pop(k[,d]) -> v, remove specified key and return the corresponding
        value.  If key is not found, d is returned if given, otherwise KeyError
        is raised.

        '''
        if key in self:
            result = self[key]
            del self[key]
            return result
        if default is self.__marker:
            raise KeyError(key)
        return default

    def setdefault(self, key, default=None):
        'od.setdefault(k[,d]) -> od.get(k,d), also set od[k]=d if k not in od'
        if key in self:
            return self[key]
        self[key] = default
        return default

    def popitem(self, last=True):
        '''od.popitem() -> (k, v), return and remove a (key, value) pair.
        Pairs are returned in LIFO order if last is true or FIFO order if false.

        '''
        if not self:
            raise KeyError('dictionary is empty')
        key = next(reversed(self) if last else iter(self))
        value = self.pop(key)
        return key, value

    def __repr__(self, _repr_running={}):
        'od.__repr__() <==> repr(od)'
        call_key = id(self), _get_ident()
        if call_key in _repr_running:
            return '...'
        _repr_running[call_key] = 1
        try:
            if not self:
                return '%s()' % (self.__class__.__name__,)
            return '%s(%r)' % (self.__class__.__name__, self.items())
        finally:
            del _repr_running[call_key]

    def __reduce__(self):
        'Return state information for pickling'
        items = [[k, self[k]] for k in self]
        inst_dict = vars(self).copy()
        for k in vars(OrderedDict()):
            inst_dict.pop(k, None)
        if inst_dict:
            return (self.__class__, (items,), inst_dict)
        return self.__class__, (items,)

    def copy(self):
        'od.copy() -> a shallow copy of od'
        return self.__class__(self)

    @classmethod
    def fromkeys(cls, iterable, value=None):
        '''OD.fromkeys(S[, v]) -> New ordered dictionary with keys from S.
        If not specified, the value defaults to None.

        '''
        self = cls()
        for key in iterable:
            self[key] = value
        return self

    def __eq__(self, other):
        '''od.__eq__(y) <==> od==y.  Comparison to another OD is order-sensitive
        while comparison to a regular mapping is order-insensitive.

        '''
        if isinstance(other, OrderedDict):
            return dict.__eq__(self, other) and all(_imap(_eq, self, other))
        return dict.__eq__(self, other)

    def __ne__(self, other):
        'od.__ne__(y) <==> od!=y'
        return not self == other

    # -- the following methods support python 3.x style dictionary views --

    def viewkeys(self):
        "od.viewkeys() -> a set-like object providing a view on od's keys"
        return KeysView(self)

    def viewvalues(self):
        "od.viewvalues() -> an object providing a view on od's values"
        return ValuesView(self)

    def viewitems(self):
        "od.viewitems() -> a set-like object providing a view on od's items"
        return ItemsView(self) 
    
  

三、默认字典(defaultdict)

学前需求：

 
    
     
       
       
         有以下值集合 [ 
         11 
         , 
         22 
         , 
         33 
         , 
         44 
         , 
         55 
         , 
         66 
         , 
         77 
         , 
         88 
         , 
         99 
         , 
         90. 
         ..]，将全部大于  
         66  
         的值保存至字典的第一个key中，将小于  
         66  
         的值保存至第二个key的值中。 
        
 
         即： { 
         'k1' 
         : 大于 
         66  
         ,  
         'k2' 
         : 小于 
         66 
         } 
        
 
     
 
    
  

 
    
  
values = [11, 22, 33,44,55,66,77,88,99,90]

my_dict = {}

for value in  values:
    if value>66:
        if my_dict.has_key('k1'):
            my_dict['k1'].append(value)
        else:
            my_dict['k1'] = [value]
    else:
        if my_dict.has_key('k2'):
            my_dict['k2'].append(value)
        else:
            my_dict['k2'] = [value] 
    
  

 
from collections import defaultdict

values = [11, 22, 33,44,55,66,77,88,99,90]

my_dict = defaultdict(list)

for value in  values:
    if value>66:
        my_dict['k1'].append(value)
    else:
        my_dict['k2'].append(value)

defaultdict是对字典的类型的补充，他默认给字典的值设置了一个类型。

 
    
  
class defaultdict(dict):
    """
    defaultdict(default_factory[, ...]) --> dict with default factory
    
    The default factory is called without arguments to produce
    a new value when a key is not present, in __getitem__ only.
    A defaultdict compares equal to a dict with the same items.
    All remaining arguments are treated the same as if they were
    passed to the dict constructor, including keyword arguments.
    """
    def copy(self): # real signature unknown; restored from __doc__
        """ D.copy() -> a shallow copy of D. """
        pass

    def __copy__(self, *args, **kwargs): # real signature unknown
        """ D.copy() -> a shallow copy of D. """
        pass

    def __getattribute__(self, name): # real signature unknown; restored from __doc__
        """ x.__getattribute__('name') <==> x.name """
        pass

    def __init__(self, default_factory=None, **kwargs): # known case of _collections.defaultdict.__init__
        """
        defaultdict(default_factory[, ...]) --> dict with default factory
        
        The default factory is called without arguments to produce
        a new value when a key is not present, in __getitem__ only.
        A defaultdict compares equal to a dict with the same items.
        All remaining arguments are treated the same as if they were
        passed to the dict constructor, including keyword arguments.
        
        # (copied from class doc)
        """
        pass

    def __missing__(self, key): # real signature unknown; restored from __doc__
        """
        __missing__(key) # Called by __getitem__ for missing key; pseudo-code:
          if self.default_factory is None: raise KeyError((key,))
          self[key] = value = self.default_factory()
          return value
        """
        pass

    def __reduce__(self, *args, **kwargs): # real signature unknown
        """ Return state information for pickling. """
        pass

    def __repr__(self): # real signature unknown; restored from __doc__
        """ x.__repr__() <==> repr(x) """
        pass

    default_factory = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
    """Factory for default value called by __missing__().""" 
    
  

四、可命名元组(namedtuple)

根据nametuple能够建立一个包含tuple全部功能以及其余功能的类型。

 
         import  
         collections 
        
         Mytuple  
         =  
         collections.namedtuple( 
         'Mytuple' 
         ,[ 
         'x' 
         ,  
         'y' 
         ,  
         'z' 
         ])

 
    
  
class Mytuple(__builtin__.tuple)
 |  Mytuple(x, y)
 |  
 |  Method resolution order:
 |      Mytuple
 |      __builtin__.tuple
 |      __builtin__.object
 |  
 |  Methods defined here:
 |  
 |  __getnewargs__(self)
 |      Return self as a plain tuple.  Used by copy and pickle.
 |  
 |  __getstate__(self)
 |      Exclude the OrderedDict from pickling
 |  
 |  __repr__(self)
 |      Return a nicely formatted representation string
 |  
 |  _asdict(self)
 |      Return a new OrderedDict which maps field names to their values
 |  
 |  _replace(_self, **kwds)
 |      Return a new Mytuple object replacing specified fields with new values
 |  
 |  ----------------------------------------------------------------------
 |  Class methods defined here:
 |  
 |  _make(cls, iterable, new=<built-in method __new__ of type object>, len=<built-in function len>) from __builtin__.type
 |      Make a new Mytuple object from a sequence or iterable
 |  
 |  ----------------------------------------------------------------------
 |  Static methods defined here:
 |  
 |  __new__(_cls, x, y)
 |      Create new instance of Mytuple(x, y)
 |  
 |  ----------------------------------------------------------------------
 |  Data descriptors defined here:
 |  
 |  __dict__
 |      Return a new OrderedDict which maps field names to their values
 |  
 |  x
 |      Alias for field number 0
 |  
 |  y
 |      Alias for field number 1
 |  
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |  
 |  _fields = ('x', 'y')
 |  
 |  ----------------------------------------------------------------------
 |  Methods inherited from __builtin__.tuple:
 |  
 |  __add__(...)
 |      x.__add__(y) <==> x+y
 |  
 |  __contains__(...)
 |      x.__contains__(y) <==> y in x
 |  
 |  __eq__(...)
 |      x.__eq__(y) <==> x==y
 |  
 |  __ge__(...)
 |      x.__ge__(y) <==> x>=y
 |  
 |  __getattribute__(...)
 |      x.__getattribute__('name') <==> x.name
 |  
 |  __getitem__(...)
 |      x.__getitem__(y) <==> x[y]
 |  
 |  __getslice__(...)
 |      x.__getslice__(i, j) <==> x[i:j]
 |      
 |      Use of negative indices is not supported.
 |  
 |  __gt__(...)
 |      x.__gt__(y) <==> x>y
 |  
 |  __hash__(...)
 |      x.__hash__() <==> hash(x)
 |  
 |  __iter__(...)
 |      x.__iter__() <==> iter(x)
 |  
 |  __le__(...)
 |      x.__le__(y) <==> x<=y
 |  
 |  __len__(...)
 |      x.__len__() <==> len(x)
 |  
 |  __lt__(...)
 |      x.__lt__(y) <==> x<y
 |  
 |  __mul__(...)
 |      x.__mul__(n) <==> x*n
 |  
 |  __ne__(...)
 |      x.__ne__(y) <==> x!=y
 |  
 |  __rmul__(...)
 |      x.__rmul__(n) <==> n*x
 |  
 |  __sizeof__(...)
 |      T.__sizeof__() -- size of T in memory, in bytes
 |  
 |  count(...)
 |      T.count(value) -> integer -- return number of occurrences of value
 |  
 |  index(...)
 |      T.index(value, [start, [stop]]) -> integer -- return first index of value.
 |      Raises ValueError if the value is not present.

Mytuple 
    
  

五、双向队列(deque)

一个线程安全的双向队列

 
    
  
class deque(object):
    """
    deque([iterable[, maxlen]]) --> deque object
    
    Build an ordered collection with optimized access from its endpoints.
    """
    def append(self, *args, **kwargs): # real signature unknown
        """ Add an element to the right side of the deque. """
        pass

    def appendleft(self, *args, **kwargs): # real signature unknown
        """ Add an element to the left side of the deque. """
        pass

    def clear(self, *args, **kwargs): # real signature unknown
        """ Remove all elements from the deque. """
        pass

    def count(self, value): # real signature unknown; restored from __doc__
        """ D.count(value) -> integer -- return number of occurrences of value """
        return 0

    def extend(self, *args, **kwargs): # real signature unknown
        """ Extend the right side of the deque with elements from the iterable """
        pass

    def extendleft(self, *args, **kwargs): # real signature unknown
        """ Extend the left side of the deque with elements from the iterable """
        pass

    def pop(self, *args, **kwargs): # real signature unknown
        """ Remove and return the rightmost element. """
        pass

    def popleft(self, *args, **kwargs): # real signature unknown
        """ Remove and return the leftmost element. """
        pass

    def remove(self, value): # real signature unknown; restored from __doc__
        """ D.remove(value) -- remove first occurrence of value. """
        pass

    def reverse(self): # real signature unknown; restored from __doc__
        """ D.reverse() -- reverse *IN PLACE* """
        pass

    def rotate(self, *args, **kwargs): # real signature unknown
        """ Rotate the deque n steps to the right (default n=1).  If n is negative, rotates left. """
        pass

    def __copy__(self, *args, **kwargs): # real signature unknown
        """ Return a shallow copy of a deque. """
        pass

    def __delitem__(self, y): # real signature unknown; restored from __doc__
        """ x.__delitem__(y) <==> del x[y] """
        pass

    def __eq__(self, y): # real signature unknown; restored from __doc__
        """ x.__eq__(y) <==> x==y """
        pass

    def __getattribute__(self, name): # real signature unknown; restored from __doc__
        """ x.__getattribute__('name') <==> x.name """
        pass

    def __getitem__(self, y): # real signature unknown; restored from __doc__
        """ x.__getitem__(y) <==> x[y] """
        pass

    def __ge__(self, y): # real signature unknown; restored from __doc__
        """ x.__ge__(y) <==> x>=y """
        pass

    def __gt__(self, y): # real signature unknown; restored from __doc__
        """ x.__gt__(y) <==> x>y """
        pass

    def __iadd__(self, y): # real signature unknown; restored from __doc__
        """ x.__iadd__(y) <==> x+=y """
        pass

    def __init__(self, iterable=(), maxlen=None): # known case of _collections.deque.__init__
        """
        deque([iterable[, maxlen]]) --> deque object
        
        Build an ordered collection with optimized access from its endpoints.
        # (copied from class doc)
        """
        pass

    def __iter__(self): # real signature unknown; restored from __doc__
        """ x.__iter__() <==> iter(x) """
        pass

    def __len__(self): # real signature unknown; restored from __doc__
        """ x.__len__() <==> len(x) """
        pass

    def __le__(self, y): # real signature unknown; restored from __doc__
        """ x.__le__(y) <==> x<=y """
        pass

    def __lt__(self, y): # real signature unknown; restored from __doc__
        """ x.__lt__(y) <==> x<y """
        pass

    @staticmethod # known case of __new__
    def __new__(S, *more): # real signature unknown; restored from __doc__
        """ T.__new__(S, ...) -> a new object with type S, a subtype of T """
        pass

    def __ne__(self, y): # real signature unknown; restored from __doc__
        """ x.__ne__(y) <==> x!=y """
        pass

    def __reduce__(self, *args, **kwargs): # real signature unknown
        """ Return state information for pickling. """
        pass

    def __repr__(self): # real signature unknown; restored from __doc__
        """ x.__repr__() <==> repr(x) """
        pass

    def __reversed__(self): # real signature unknown; restored from __doc__
        """ D.__reversed__() -- return a reverse iterator over the deque """
        pass

    def __setitem__(self, i, y): # real signature unknown; restored from __doc__
        """ x.__setitem__(i, y) <==> x[i]=y """
        pass

    def __sizeof__(self): # real signature unknown; restored from __doc__
        """ D.__sizeof__() -- size of D in memory, in bytes """
        pass

    maxlen = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default
    """maximum size of a deque or None if unbounded"""


    __hash__ = None 
    
  

注：既然有双向队列，也有单项队列（先进先出 FIFO ）

 
    
  
class Queue:
    """Create a queue object with a given maximum size.

    If maxsize is <= 0, the queue size is infinite.
    """
    def __init__(self, maxsize=0):
        self.maxsize = maxsize
        self._init(maxsize)
        # mutex must be held whenever the queue is mutating.  All methods
        # that acquire mutex must release it before returning.  mutex
        # is shared between the three conditions, so acquiring and
        # releasing the conditions also acquires and releases mutex.
        self.mutex = _threading.Lock()
        # Notify not_empty whenever an item is added to the queue; a
        # thread waiting to get is notified then.
        self.not_empty = _threading.Condition(self.mutex)
        # Notify not_full whenever an item is removed from the queue;
        # a thread waiting to put is notified then.
        self.not_full = _threading.Condition(self.mutex)
        # Notify all_tasks_done whenever the number of unfinished tasks
        # drops to zero; thread waiting to join() is notified to resume
        self.all_tasks_done = _threading.Condition(self.mutex)
        self.unfinished_tasks = 0

    def task_done(self):
        """Indicate that a formerly enqueued task is complete.

        Used by Queue consumer threads.  For each get() used to fetch a task,
        a subsequent call to task_done() tells the queue that the processing
        on the task is complete.

        If a join() is currently blocking, it will resume when all items
        have been processed (meaning that a task_done() call was received
        for every item that had been put() into the queue).

        Raises a ValueError if called more times than there were items
        placed in the queue.
        """
        self.all_tasks_done.acquire()
        try:
            unfinished = self.unfinished_tasks - 1
            if unfinished <= 0:
                if unfinished < 0:
                    raise ValueError('task_done() called too many times')
                self.all_tasks_done.notify_all()
            self.unfinished_tasks = unfinished
        finally:
            self.all_tasks_done.release()

    def join(self):
        """Blocks until all items in the Queue have been gotten and processed.

        The count of unfinished tasks goes up whenever an item is added to the
        queue. The count goes down whenever a consumer thread calls task_done()
        to indicate the item was retrieved and all work on it is complete.

        When the count of unfinished tasks drops to zero, join() unblocks.
        """
        self.all_tasks_done.acquire()
        try:
            while self.unfinished_tasks:
                self.all_tasks_done.wait()
        finally:
            self.all_tasks_done.release()

    def qsize(self):
        """Return the approximate size of the queue (not reliable!)."""
        self.mutex.acquire()
        n = self._qsize()
        self.mutex.release()
        return n

    def empty(self):
        """Return True if the queue is empty, False otherwise (not reliable!)."""
        self.mutex.acquire()
        n = not self._qsize()
        self.mutex.release()
        return n

    def full(self):
        """Return True if the queue is full, False otherwise (not reliable!)."""
        self.mutex.acquire()
        n = 0 < self.maxsize == self._qsize()
        self.mutex.release()
        return n

    def put(self, item, block=True, timeout=None):
        """Put an item into the queue.

        If optional args 'block' is true and 'timeout' is None (the default),
        block if necessary until a free slot is available. If 'timeout' is
        a non-negative number, it blocks at most 'timeout' seconds and raises
        the Full exception if no free slot was available within that time.
        Otherwise ('block' is false), put an item on the queue if a free slot
        is immediately available, else raise the Full exception ('timeout'
        is ignored in that case).
        """
        self.not_full.acquire()
        try:
            if self.maxsize > 0:
                if not block:
                    if self._qsize() == self.maxsize:
                        raise Full
                elif timeout is None:
                    while self._qsize() == self.maxsize:
                        self.not_full.wait()
                elif timeout < 0:
                    raise ValueError("'timeout' must be a non-negative number")
                else:
                    endtime = _time() + timeout
                    while self._qsize() == self.maxsize:
                        remaining = endtime - _time()
                        if remaining <= 0.0:
                            raise Full
                        self.not_full.wait(remaining)
            self._put(item)
            self.unfinished_tasks += 1
            self.not_empty.notify()
        finally:
            self.not_full.release()

    def put_nowait(self, item):
        """Put an item into the queue without blocking.

        Only enqueue the item if a free slot is immediately available.
        Otherwise raise the Full exception.
        """
        return self.put(item, False)

    def get(self, block=True, timeout=None):
        """Remove and return an item from the queue.

        If optional args 'block' is true and 'timeout' is None (the default),
        block if necessary until an item is available. If 'timeout' is
        a non-negative number, it blocks at most 'timeout' seconds and raises
        the Empty exception if no item was available within that time.
        Otherwise ('block' is false), return an item if one is immediately
        available, else raise the Empty exception ('timeout' is ignored
        in that case).
        """
        self.not_empty.acquire()
        try:
            if not block:
                if not self._qsize():
                    raise Empty
            elif timeout is None:
                while not self._qsize():
                    self.not_empty.wait()
            elif timeout < 0:
                raise ValueError("'timeout' must be a non-negative number")
            else:
                endtime = _time() + timeout
                while not self._qsize():
                    remaining = endtime - _time()
                    if remaining <= 0.0:
                        raise Empty
                    self.not_empty.wait(remaining)
            item = self._get()
            self.not_full.notify()
            return item
        finally:
            self.not_empty.release()

    def get_nowait(self):
        """Remove and return an item from the queue without blocking.

        Only get an item if one is immediately available. Otherwise
        raise the Empty exception.
        """
        return self.get(False)

    # Override these methods to implement other queue organizations
    # (e.g. stack or priority queue).
    # These will only be called with appropriate locks held

    # Initialize the queue representation
    def _init(self, maxsize):
        self.queue = deque()

    def _qsize(self, len=len):
        return len(self.queue)

    # Put a new item in the queue
    def _put(self, item):
        self.queue.append(item)

    # Get an item from the queue
    def _get(self):
        return self.queue.popleft() 
    
  

OS模块

用于提供系统级别的操做：

 
         os.getcwd()                 获取当前工做目录，即当前python脚本工做的目录路径 
        
         os.chdir( 
         "dirname" 
         )         改变当前脚本工做目录；至关于shell下cd 
        
         os.curdir                   返回当前目录: ( 
         '.' 
         ) 
        
         os.pardir                   获取当前目录的父目录字符串名：( 
         '..' 
         ) 
        
         os.makedirs( 
         'dir1/dir2' 
         )    可生成多层递归目录 
        
         os.removedirs( 
         'dirname1' 
         )   若目录为空，则删除，并递归到上一级目录，如若也为空，则删除，依此类推 
        
         os.mkdir( 
         'dirname' 
         )         生成单级目录；至关于shell中mkdir dirname 
        
         os.rmdir( 
         'dirname' 
         )         删除单级空目录，若目录不为空则没法删除，报错；至关于shell中rmdir dirname 
        
         os.listdir( 
         'dirname' 
         )       列出指定目录下的全部文件和子目录，包括隐藏文件，并以列表方式打印 
        
         os.remove()                 删除一个文件 
        
         os.rename( 
         "oldname" 
         , 
         "new" 
         )  重命名文件 
         / 
         目录 
        
         os.stat( 
         'path/filename' 
         )    获取文件 
         / 
         目录信息 
        
         os.sep                      操做系统特定的路径分隔符，win下为 
         "\\",Linux下为" 
         / 
         " 
        
         os.linesep                  当前平台使用的行终止符，win下为 
         "\t\n" 
         ,Linux下为 
         "\n" 
        
         os.pathsep                  用于分割文件路径的字符串 
        
         os.name                     字符串指示当前使用平台。win 
         - 
         > 
         'nt' 
         ; Linux 
         - 
         > 
         'posix' 
        
         os.system( 
         "bash command" 
         )   运行shell命令，直接显示 
        
         os.environ                  获取系统环境变量 
        
         os.path.abspath(path)       返回path规范化的绝对路径 
        
         os.path.split(path)         将path分割成目录和文件名二元组返回 
        
         os.path.dirname(path)       返回path的目录。其实就是os.path.split(path)的第一个元素 
        
         os.path.basename(path)      返回path最后的文件名。如何path以／或\结尾，那么就会返回空值。即os.path.split(path)的第二个元素 
        
         os.path.exists(path)        若是path存在，返回 
         True 
         ；若是path不存在，返回 
         False 
        
         os.path.isabs(path)         若是path是绝对路径，返回 
         True 
        
         os.path.isfile(path)        若是path是一个存在的文件，返回 
         True 
         。不然返回 
         False 
        
         os.path.isdir(path)         若是path是一个存在的目录，则返回 
         True 
         。不然返回 
         False 
        
         os.path.join(path1[, path2[, ...]])  将多个路径组合后返回，第一个绝对路径以前的参数将被忽略 
        
         os.path.getatime(path)      返回path所指向的文件或者目录的最后存取时间 
        
         os.path.getmtime(path)      返回path所指向的文件或者目录的最后修改时间

hashlib

用于加密相关的操做，代替了md5模块和sha模块，主要提供 SHA1, SHA224, SHA256, SHA384, SHA512 ，MD5 算法

 
         import  
         hashlib 
        
         # ######## md5 ######## 
        
         hash  
         =  
         hashlib.md5() 
        
         # help(hash.update) 
        
         hash 
         .update(bytes( 
         'admin' 
         , encoding 
         = 
         'utf-8' 
         )) 
        
         print 
         ( 
         hash 
         .hexdigest()) 
        
         print 
         ( 
         hash 
         .digest()) 
        
         ######## sha1 ######## 
        
         hash  
         =  
         hashlib.sha1() 
        
         hash 
         .update(bytes( 
         'admin' 
         , encoding 
         = 
         'utf-8' 
         )) 
        
         print 
         ( 
         hash 
         .hexdigest()) 
        
         # ######## sha256 ######## 
        
         hash  
         =  
         hashlib.sha256() 
        
         hash 
         .update(bytes( 
         'admin' 
         , encoding 
         = 
         'utf-8' 
         )) 
        
         print 
         ( 
         hash 
         .hexdigest()) 
        
         # ######## sha384 ######## 
        
         hash  
         =  
         hashlib.sha384() 
        
         hash 
         .update(bytes( 
         'admin' 
         , encoding 
         = 
         'utf-8' 
         )) 
        
         print 
         ( 
         hash 
         .hexdigest()) 
        
         # ######## sha512 ######## 
        
         hash  
         =  
         hashlib.sha512() 
        
         hash 
         .update(bytes( 
         'admin' 
         , encoding 
         = 
         'utf-8' 
         )) 
        
         print 
         ( 
         hash 
         .hexdigest())

以上加密算法虽然依然很是厉害，但时候存在缺陷，即：经过撞库能够反解。因此，有必要对加密算法中添加自定义key再来作加密。

 
         import  
         hashlib 
        
         # ######## md5 ######## 
        
         hash  
         =  
         hashlib.md5(bytes( 
         '898oaFs09f' 
         ,encoding 
         = 
         "utf-8" 
         )) 
        
         hash 
         .update(bytes( 
         'admin' 
         ,encoding 
         = 
         "utf-8" 
         )) 
        
         print 
         ( 
         hash 
         .hexdigest())

python内置还有一个 hmac 模块，它内部对咱们建立 key 和内容进行进一步的处理而后再加密

 
         import  
         hmac 
        
         h  
         =  
         hmac.new(bytes( 
         '898oaFs09f' 
         ,encoding 
         = 
         "utf-8" 
         )) 
        
         h.update(bytes( 
         'admin' 
         ,encoding 
         = 
         "utf-8" 
         )) 
        
         print 
         (h.hexdigest())

 
    
  
import hashlib

def hash(pwd):
    hash = hashlib.md5(bytes("zhangyanlin",encoding='utf-8'))
    hash.update(bytes(pwd,encoding='utf-8'))
    return hash.hexdigest()

def login(username,passwd):
    with open("db",'r',encoding="utf-8") as f:
        for i in f:
            i  = i.strip().split("|")
            if i[0] == username and i[1] == hash(passwd):
                return True

def zc_login(username,passwd):
    with open("db","a",encoding='utf-8') as f:
        use_pwd =  username + "|" + hash(passwd) + "\n"
        f.write(use_pwd)
        return True


choice = input("1.登陆；2.注册 \n请您选择：")
if choice == "1":
    for i in range(3):
        user = input("请输入用户名：")
        pwd  = input("请输入密码：")
        login_1 = login(user,pwd)
        if login_1:
            print("登陆成功")
            break
        else:
            print('登陆失败！')
            continue
elif choice == "2":
    user = input("请输入用户名：")
    pwd  = input("请输入密码：")
    login_2 = zc_login(user,pwd)
    if login_2:
        print("注册成功！") 
    
  

XML

XML是实现不一样语言或程序之间进行数据交换的协议，XML文件格式以下：

 
    
     
       
       
         <data> 
        
 
              
         <country name 
         = 
         "Liechtenstein" 
         > 
        
 
                  
         <rank updated 
         = 
         "yes" 
         > 
         2 
         < 
         / 
         rank> 
        
 
                  
         <year> 
         2023 
         < 
         / 
         year> 
        
 
                  
         <gdppc> 
         141100 
         < 
         / 
         gdppc> 
        
 
                  
         <neighbor direction 
         = 
         "E"  
         name 
         = 
         "Austria"  
         / 
         > 
        
 
                  
         <neighbor direction 
         = 
         "W"  
         name 
         = 
         "Switzerland"  
         / 
         > 
        
 
              
         < 
         / 
         country> 
        
 
              
         <country name 
         = 
         "Singapore" 
         > 
        
 
                  
         <rank updated 
         = 
         "yes" 
         > 
         5 
         < 
         / 
         rank> 
        
 
                  
         <year> 
         2026 
         < 
         / 
         year> 
        
 
                  
         <gdppc> 
         59900 
         < 
         / 
         gdppc> 
        
 
                  
         <neighbor direction 
         = 
         "N"  
         name 
         = 
         "Malaysia"  
         / 
         > 
        
 
              
         < 
         / 
         country> 
        
 
              
         <country name 
         = 
         "Panama" 
         > 
        
 
                  
         <rank updated 
         = 
         "yes" 
         > 
         69 
        
 
     
 
    
  