Python成长之路（常用模块学习）

 #_*_coding:utf-8_*_

 __author__ = 'Alex Li'

 import time

 # print(time.clock()) #返回处理器时间,3.3开始已废弃 , 改成了time.process_time()测量处理器运算时间,不包括sleep时间,不稳定,mac上测不出来

 # print(time.altzone)  #返回与utc时间的时间差,以秒计算\

 # print(time.asctime()) #返回时间格式"Fri Aug 19 11:14:16 2016",

 # print(time.localtime()) #返回本地时间 的struct time对象格式

 # print(time.gmtime(time.time()-800000)) #返回utc时间的struc时间对象格式

 # print(time.asctime(time.localtime())) #返回时间格式"Fri Aug 19 11:14:16 2016",

 #print(time.ctime()) #返回Fri Aug 19 12:38:29 2016 格式, 同上

 # 日期字符串 转成  时间戳

 # string_2_struct = time.strptime("2016/05/22","%Y/%m/%d") #将 日期字符串 转成 struct时间对象格式

 # print(string_2_struct)

 # #

 # struct_2_stamp = time.mktime(string_2_struct) #将struct时间对象转成时间戳

 # print(struct_2_stamp)

 #将时间戳转为字符串格式

 # print(time.gmtime(time.time()-86640)) #将utc时间戳转换成struct_time格式

 # print(time.strftime("%Y-%m-%d %H:%M:%S",time.gmtime()) ) #将utc struct_time格式转成指定的字符串格式

 #时间加减

 import datetime

 # print(datetime.datetime.now()) #返回 2016-08-19 12:47:03.941925

 #print(datetime.date.fromtimestamp(time.time()) )  # 时间戳直接转成日期格式 2016-08-19

 # print(datetime.datetime.now() )

 # print(datetime.datetime.now() + datetime.timedelta(3)) #当前时间+3天

 # print(datetime.datetime.now() + datetime.timedelta(-3)) #当前时间-3天

 # print(datetime.datetime.now() + datetime.timedelta(hours=3)) #当前时间+3小时

 # print(datetime.datetime.now() + datetime.timedelta(minutes=30)) #当前时间+30分

 #

 # c_time  = datetime.datetime.now()

 # print(c_time.replace(minute=3,hour=2)) #时间替换

 import random

 print(random.random())

 print(random.randint(1,2)) #在1-2之间取一个随机数字

 print(random.randrange(1,10)) #在1-10之间取一个随机数字

 import random

 checkcode = ''

 for i in range(4):

     current = random.randrange(0,4)

     if current != i:

         temp = chr(random.randint(65,90))

     else:

         temp = random.randint(0,9)

         checkcode += str(temp)

 print (checkcode)    

 os.getcwd() 获取当前工作目录，即当前python脚本工作的目录路径

 os.chdir("dirname")  改变当前脚本工作目录；相当于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('dirname1/dirname2')    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；相当于shell中mkdir dirname

 os.rmdir('dirname')    删除单级空目录，若目录不为空则无法删除，报错；相当于shell中rmdir dirname

 os.listdir('dirname')    列出指定目录下的所有文件和子目录，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","newname")  重命名文件/目录

 os.stat('path/filename')  获取文件/目录信息

 os.sep    输出操作系统特定的路径分隔符，win下为"\\",Linux下为"/"

 os.linesep    输出当前平台使用的行终止符，win下为"\t\n",Linux下为"\n"

 os.pathsep    输出用于分割文件路径的字符串

 os.name    输出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)  如果path存在，返回True；如果path不存在，返回False

 os.path.isabs(path)  如果path是绝对路径，返回True

 os.path.isfile(path)  如果path是一个存在的文件，返回True。否则返回False

 os.path.isdir(path)  如果path是一个存在的目录，则返回True。否则返回False

 os.path.join(path1[, path2[, ...]])  将多个路径组合后返回，第一个绝对路径之前的参数将被忽略

 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

 sys.argv           命令行参数List，第一个元素是程序本身路径

 sys.exit(n)        退出程序，正常退出时exit(0)

 sys.version        获取Python解释程序的版本信息

 sys.maxint         最大的Int值

 sys.path           返回模块的搜索路径，初始化时使用PYTHONPATH环境变量的值

 sys.platform       返回操作系统平台名称

 sys.stdout.write('please:')

 val = sys.stdin.readline()[:-1]

 import shelve

 d = shelve.open('shelve_test') #打开一个文件

 class Test(object):

     def __init__(self,n):

         self.n = n

 t = Test(123)

 t2 = Test(123334)

 name = ["alex","rain","test"]

 d["test"] = name #持久化列表

 d["t1"] = t      #持久化类

 d["t2"] = t2

 d.close()

 <?xml version="1.0"?>

 <data>

     <country name="Liechtenstein">

         <rank updated="yes">2</rank>

         <year>2008</year>

         <gdppc>141100</gdppc>

         <neighbor name="Austria" direction="E"/>

         <neighbor name="Switzerland" direction="W"/>

     </country>

     <country name="Singapore">

         <rank updated="yes">5</rank>

         <year>2011</year>

         <gdppc>59900</gdppc>

         <neighbor name="Malaysia" direction="N"/>

     </country>

     <country name="Panama">

         <rank updated="yes">69</rank>

         <year>2011</year>

         <gdppc>13600</gdppc>

         <neighbor name="Costa Rica" direction="W"/>

         <neighbor name="Colombia" direction="E"/>

     </country>

 </data>

 import xml.etree.ElementTree as ET

 tree = ET.parse("xmltest.xml")

 root = tree.getroot()

 print(root.tag)

 #遍历xml文档

 for child in root:

     print(child.tag, child.attrib)

     for i in child:

         print(i.tag,i.text)

 #只遍历year 节点

 for node in root.iter('year'):

     print(node.tag,node.text)

 import xml.etree.ElementTree as ET

 tree = ET.parse("xmltest.xml")

 root = tree.getroot()

 #修改

 for node in root.iter('year'):

     new_year = int(node.text) + 1

     node.text = str(new_year)

     node.set("updated","yes")

 tree.write("xmltest.xml")

 #删除node

 for country in root.findall('country'):

    rank = int(country.find('rank').text)

    if rank > 50:

      root.remove(country)

 tree.write('output.xml')

 import xml.etree.ElementTree as ET

 new_xml = ET.Element("namelist")

 name = ET.SubElement(new_xml,"name",attrib={"enrolled":"yes"})

 age = ET.SubElement(name,"age",attrib={"checked":"no"})

 sex = ET.SubElement(name,"sex")

 sex.text = ''

 name2 = ET.SubElement(new_xml,"name",attrib={"enrolled":"no"})

 age = ET.SubElement(name2,"age")

 age.text = ''

 et = ET.ElementTree(new_xml) #生成文档对象

 et.write("test.xml", encoding="utf-8",xml_declaration=True)

 ET.dump(new_xml) #打印生成的格式 

 [DEFAULT]

 ServerAliveInterval = 45

 Compression = yes

 CompressionLevel = 9

 ForwardX11 = yes

 [bitbucket.org]

 User = hg

 [topsecret.server.com]

 Port = 50022

 ForwardX11 = no

 import configparser

 config = configparser.ConfigParser()

 config["DEFAULT"] = {'ServerAliveInterval': '',

                       'Compression': 'yes',

                      'CompressionLevel': ''}

 config['bitbucket.org'] = {}

 config['bitbucket.org']['User'] = 'hg'

 config['topsecret.server.com'] = {}

 topsecret = config['topsecret.server.com']

 topsecret['Host Port'] = ''     # mutates the parser

 topsecret['ForwardX11'] = 'no'  # same here

 config['DEFAULT']['ForwardX11'] = 'yes'

 with open('example.ini', 'w') as configfile:

    config.write(configfile) 

 >>> import configparser

 >>> config = configparser.ConfigParser()

 >>> config.sections()

 []

 >>> config.read('example.ini')

 ['example.ini']

 >>> config.sections()

 ['bitbucket.org', 'topsecret.server.com']

 >>> 'bitbucket.org' in config

 True

 >>> 'bytebong.com' in config

 False

 >>> config['bitbucket.org']['User']

 'hg'

 >>> config['DEFAULT']['Compression']

 'yes'

 >>> topsecret = config['topsecret.server.com']

 >>> topsecret['ForwardX11']

 'no'

 >>> topsecret['Port']

 ''

 >>> for key in config['bitbucket.org']: print(key)

 ...

 user

 compressionlevel

 serveraliveinterval

 compression

 forwardx11

 >>> config['bitbucket.org']['ForwardX11']

 'yes'   

 [section1]

 k1 = v1

 k2:v2

 [section2]

 k1 = v1

 import ConfigParser

 config = ConfigParser.ConfigParser()

 config.read('i.cfg')

 # ########## 读 ##########

 #secs = config.sections()

 #print secs

 #options = config.options('group2')

 #print options

 #item_list = config.items('group2')

 #print item_list

 #val = config.get('group1','key')

 #val = config.getint('group1','key')

 # ########## 改写 ##########

 #sec = config.remove_section('group1')

 #config.write(open('i.cfg', "w"))

 #sec = config.has_section('wupeiqi')

 #sec = config.add_section('wupeiqi')

 #config.write(open('i.cfg', "w"))

 #config.set('group2','k1',11111)

 #config.write(open('i.cfg', "w"))

 #config.remove_option('group2','age')

 #config.write(open('i.cfg', "w"))

import hashlib

m = hashlib.md5()

m.update(b"Hello")

m.update(b"It's me")

print(m.digest())

m.update(b"It's been a long time since last time we ...")

print(m.digest()) #2进制格式hash

print(len(m.hexdigest())) #16进制格式hash

'''

def digest(self, *args, **kwargs): # real signature unknown

    """ Return the digest value as a string of binary data. """

    pass

def hexdigest(self, *args, **kwargs): # real signature unknown

    """ Return the digest value as a string of hexadecimal digits. """

    pass

'''

import hashlib

# ######## md5 ########

hash = hashlib.md5()

hash.update('admin')

print(hash.hexdigest())

# ######## sha1 ########

hash = hashlib.sha1()

hash.update('admin')

print(hash.hexdigest())

# ######## sha256 ########

hash = hashlib.sha256()

hash.update('admin')

print(hash.hexdigest())

# ######## sha384 ########

hash = hashlib.sha384()

hash.update('admin')

print(hash.hexdigest())

# ######## sha512 ########

hash = hashlib.sha512()

hash.update('admin')

print(hash.hexdigest())    

 import hmac

 h = hmac.new(b'天王盖地虎', b'宝塔镇河妖')

 print h.hexdigest()

 >>> subprocess.run(["ls", "-l"])  # doesn't capture output

 CompletedProcess(args=['ls', '-l'], returncode=0)

 >>> subprocess.run("exit 1", shell=True, check=True)

 Traceback (most recent call last):

   ...

 subprocess.CalledProcessError: Command 'exit 1' returned non-zero exit status 1

 >>> subprocess.run(["ls", "-l", "/dev/null"], stdout=subprocess.PIPE)

 CompletedProcess(args=['ls', '-l', '/dev/null'], returncode=0,

 stdout=b'crw-rw-rw- 1 root root 1, 3 Jan 23 16:23 /dev/null\n')