python第五节

一、定义模块:
  模块:用来从逻辑上组织python代码(变量、函数、类、逻辑:实现一个功能),本质就是以.py结尾的python文件(文件名:test.py ,对应的模块名就是test)
  包:用来从逻辑上组织模块的,本质就是一个目录(必须带有__init__.py的文件)
二、导入方法:
  1、import module_XP
#命名为module_XP.py
#需要导入的模块内容
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
name = "XP"
def say_hallo():
print("hello XP")
########################
#导入模块
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
import module_XP
print(module_XP.name)
module_XP.say_hallo()
执行结果:
XP
hello XP
 2、from module_alex import logger as logger_XP #别名

  当要导入的模块与本模块命名重复时,别名要导入的模块可以解决这个问题
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
name = "XP"
def say_hallo():
print("hello XP")
def logger():
print("in the module_XP")
def running():
pass
##################
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
from module_XP import logger as logger_XP
def logger():
print("in the main")
logger()
logger_XP()
##执行结果:
in the main
in the module_XP


3、导入一个包实际的本质就是导入一个__init__.py

  包package_test里面的init文件
1 #!/usr/bin/env python
2 # -*- coding: utf-8 -*-
3 # Author :XP
4 print("from test package package_test")
现在把package_testp_test文件导入p_test
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
import package_test
##执行结果:
from test package package_test
 4、当文件目录不再同一级目录之后该如何调用

  -module_test

    -main.py

  -module_XP.py

  现在main.py去调用module_XP.py
#module_XP.py文件
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
name = "XP"
def say_hallo():
print("hello XP")
def logger():
print("in the module_XP")
def running():
pass
##main.py文件
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
#from module_XP import logger as logger_XP
import sys,os
x = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
#print(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
sys.path.append(x)
import module_XP
module_XP.say_hallo()
module_XP.logger()
####
#执行结果:
hello XP
in the module_XP

5、如何导入一个包

  -package_test

    -test1.py

    -__init__.py

  -p_test.py
#init文件
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
print("from test package package_test")
from . import test1
#test1文件
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
def test():
print("in the test1")
###调用文件
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Author :XP
import package_test ###执行init.py文件
package_test.test1.test()
#执行结果:
from test package package_test
in the test1
####达到的目的就是在同一级目录倒入一个包的文件,中间通过init文件调度
总结

  import module_alex
  import module_alex,module2_alex #调用多个模块
  for module_alex import * ###不建议用
  from module_alex import m1,m2,m3 ##调用一个模块中的多个小模块
  from module_alex import logger as logger_alex ###别名
三、import本质(路径搜索和搜索路径)

  导入模块的本质就是把python文件解释一遍

  import moile_name ------->module_name.py ----->module_name.py的路径----->sys.path
导入包的本质就是在执行这个包里面的__init__.py文件

四、导入优化
  from module_test import tset
def loggr():
test()
print('in the loggr')
def search():
test()
print('in the search')
五、模块的分类
 a:标准库(内置)

 b:开源模块

 c:自定义模块

  1、标准库

  a、time和datetime

  在Python中,通常有这几种方式来表示时间:1)时间戳 2)格式化的时间字符串 3)元组(struct_time)共九个元素。由于Python的time模块实现主要调用C库,所以各个平台可能有所不同。

  UTC(Coordinated Universal Time,世界协调时)亦即格林威治天文时间,世界标准时间。在中国为UTC+8。DST(Daylight Saving Time)即夏令时。

  时间戳(timestamp)的方式:通常来说,时间戳表示的是从1970年1月1日00:00:00开始按秒计算的偏移量。我们运行“type(time.time())”,返回的是float类型。返回时间戳方式的函数主要有time(),clock()等。

  元组(struct_time)方式:struct_time元组共有9个元素,返回struct_time的函数主要有gmtime(),localtime(),strptime()。下面列出这种方式元组中的几个元素:

  1)time.localtime([secs]):将一个时间戳转换为当前时区的struct_time。secs参数未提供,则以当前时间为准。

>>> time.localtime()
time.struct_time(tm_year=2011, tm_mon=5, tm_mday=5, tm_hour=14, tm_min=14, tm_sec=50, tm_wday=3, tm_yday=125, tm_isdst=0)
>>> time.localtime(1304575584.1361799)
time.struct_time(tm_year=2011, tm_mon=5, tm_mday=5, tm_hour=14, tm_min=6, tm_sec=24, tm_wday=3, tm_yday=125, tm_isdst=0)

 2)time.gmtime([secs]):和localtime()方法类似,gmtime()方法是将一个时间戳转换为UTC时区(0时区)的struct_time。

>>>time.gmtime()
2 time.struct_time(tm_year=2011, tm_mon=5, tm_mday=5, tm_hour=6, tm_min=19, tm_sec=48, tm_wday=3, tm_yday=125, tm_isdst=0)

4)time.mktime(t):将一个struct_time转化为时间戳。

1 >>> time.mktime(time.localtime())
2 1304576839.0
  5)time.sleep(secs):线程推迟指定的时间运行。单位为秒。

  6)time.clock():这个需要注意,在不同的系统上含义不同。 在UNIX系统上,它返回的是“进程时间”,它是用秒表示的浮点数(时间戳)。而在WINDOWS中,第一次调用,返回的是进程运行的实际时间。而第二次 之后的调用是自第一次调用以后到现在的运行时间。(实际上是以WIN32上QueryPerformanceCounter()为基础,它比毫秒表示更为 精确)

import time
if __name__ == '__main__':
time.sleep(1)
print "clock1:%s" % time.clock()
time.sleep(1)
print "clock2:%s" % time.clock()
time.sleep(1)
print "clock3:%s" % time.clock()
执行结果:

1 clock1:3.35238137808e-006
2 clock2:1.00004944763
3 clock3:2.00012040636
其中第一个clock()输出的是程序运行时间
  第二、三个clock()输出的都是与第一个clock的时间间隔

  7)time.asctime([t]):把一个表示时间的元组或者struct_time表示为这种形式:'Sun Jun 20 23:21:05 1993'。如果没有参数,将会将time.localtime()作为参数传入。

1 >>> time.asctime()
2 'Thu May 5 14:55:43 2011'
  8)time.ctime([secs]):把一个时间戳(按秒计算的浮点数)转化为time.asctime()的形式。如果参数未给或者为None的时候,将会默认time.time()为参数。它的作用相当于time.asctime(time.localtime(secs))。
>>> time.ctime()
'Thu May 5 14:58:09 2011'
>>> time.ctime(time.time())
'Thu May 5 14:58:39 2011'
>>> time.ctime(1304579615)
'Thu May 5 15:13:35 2011'
 9)time.strftime(format[, t]): 把一个代表时间的元组或者struct_time(如由time.localtime()和time.gmtime()返回)转化为格式化的时间字符串。 如果t未指定,将传入time.localtime()。如果元组中任何一个元素越界,ValueError的错误将会被抛出。

1 >>> time.strftime("%Y-%m-%d %X", time.localtime())
2 '2011-05-05 16:37:06'
  10)time.strptime(string[, format]):把一个格式化时间字符串转化为struct_time。实际上它和strftime()是逆操作。

1 >>> time.strptime('2011-05-05 16:37:06', '%Y-%m-%d %X')
2 time.struct_time(tm_year=2011, tm_mon=5, tm_mday=5, tm_hour=16, tm_min=37, tm_sec=6, tm_wday=3, tm_yday=125, tm_isdst=-1)
  在这个函数中,format默认为:"%a %b %d %H:%M:%S %Y"。

  最后,我们来对time模块进行一个总结。根据之前描述,在Python中共有三种表达方式:1)timestamp 2)tuple或者struct_time 3)格式化字符串。

  时间转换关系

#_*_coding:utf-8_*_
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 当你没插入值的时候,,默认传入你当前时间,返回标准时间第一时区

# 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() ) 获取当前时间
# 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
####################格式参照####################
%a 本地(locale)简化星期名称
%A 本地完整星期名称
%b 本地简化月份名称
%B 本地完整月份名称
%c 本地相应的日期和时间表示
%d 一个月中的第几天(01 - 31)
%H 一天中的第几个小时(24小时制,00 - 23)
%I 第几个小时(12小时制,01 - 12)
%j 一年中的第几天(001 - 366)
%m 月份(01 - 12)
%M 分钟数(00 - 59)
%p 本地am或者pm的相应符 一
%S 秒(01 - 61) 二
%U 一年中的星期数。(00 - 53星期天是一个星期的开始。)第一个星期天之前的所有天数都放在第0周。 三
%w 一个星期中的第几天(0 - 6,0是星期天) 三
%W 和%U基本相同,不同的是%W以星期一为一个星期的开始。
%x 本地相应日期
%X 本地相应时间
%y 去掉世纪的年份(00 - 99)
%Y 完整的年份
%Z 时区的名字(如果不存在为空字符)
%% ‘%’字符

##执行结果:
3.9473128470428115e-07
-32400
Tue Aug 23 15:21:55 2016
time.struct_time(tm_year=2016, tm_mon=8, tm_mday=23, tm_hour=15, tm_min=21, tm_sec=55, tm_wday=1, tm_yday=236, tm_isdst=0)
time.struct_time(tm_year=2016, tm_mon=8, tm_mday=14, tm_hour=1, tm_min=8, tm_sec=35, tm_wday=6, tm_yday=227, tm_isdst=0)
Tue Aug 23 15:21:55 2016
Tue Aug 23 15:21:55 2016
time.struct_time(tm_year=2016, tm_mon=5, tm_mday=22, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=6, tm_yday=143, tm_isdst=-1)
1463846400.0
time.struct_time(tm_year=2016, tm_mon=8, tm_mday=22, tm_hour=7, tm_min=17, tm_sec=55, tm_wday=0, tm_yday=235, tm_isdst=0)
2016-08-23 07:21:55
2016-08-23 15:21:55.438771
2016-08-23
2016-08-23 15:21:55.438771
2016-08-26 15:21:55.438771
2016-08-20 15:21:55.438771
2016-08-23 18:21:55.438771
2016-08-23 15:51:55.438771
2016-08-23 02:03:55.438771

执行结果:一一对应

 b、random模块
#!/usr/bin/env python
#_*_encoding: utf-8_*_
import random
print (random.random()) #0.6445010863311293
#random.random()用于生成一个0到1的随机符点数: 0 <= n < 1.0
print (random.randint(1,7)) #4
#random.randint()的函数原型为:random.randint(a, b),用于生成一个指定范围内的整数。
# 其中参数a是下限,参数b是上限,生成的随机数n: a <= n <= b
print (random.randrange(1,10)) #5
#random.randrange的函数原型为:random.randrange([start], stop[, step]),
# 从指定范围内,按指定基数递增的集合中 获取一个随机数。如:random.randrange(10, 100, 2),
# 结果相当于从[10, 12, 14, 16, ... 96, 98]序列中获取一个随机数。
# random.randrange(10, 100, 2)在结果上与 random.choice(range(10, 100, 2) 等效。
print(random.choice('liukuni')) #i
#random.choice从序列中获取一个随机元素。
# 其函数原型为:random.choice(sequence)。参数sequence表示一个有序类型。
# 这里要说明一下:sequence在python不是一种特定的类型,而是泛指一系列的类型。
# list, tuple, 字符串都属于sequence。有关sequence可以查看python手册数据模型这一章。
# 下面是使用choice的一些例子:
print(random.choice("学习Python"))#学
print(random.choice(["JGood","is","a","handsome","boy"])) #List
print(random.choice(("Tuple","List","Dict"))) #List
print(random.sample([1,2,3,4,5],3)) #[1, 2, 5]
#random.sample的函数原型为:random.sample(sequence, k),从指定序列中随机获取指定长度的片断。sample函数不会修改原有序列。

实际应用
#!/usr/bin/env python
# encoding: utf-8
import random
import string
#随机整数:
print( random.randint(0,99)) #70

#随机选取0到100间的偶数:
print(random.randrange(0, 101, 2)) #4

#随机浮点数:
print( random.random()) #0.2746445568079129
print(random.uniform(1, 10)) #9.887001463194844

#随机字符:
print(random.choice('abcdefg&#%^*f')) #f

#多个字符中选取特定数量的字符:
print(random.sample('abcdefghij',3)) #['f', 'h', 'd']

#随机选取字符串:
print( random.choice ( ['apple', 'pear', 'peach', 'orange', 'lemon'] )) #apple
#洗牌#
items = [1,2,3,4,5,6,7]
print(items) #[1, 2, 3, 4, 5, 6, 7]
random.shuffle(items)
print(items) #[1, 4, 7, 2, 5, 3, 6]

 生产随机验证码
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)

c、os模块

  提供对操作系统进行调用的接口
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"\r\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

d、sys模块
sys.argv 命令行参数List,第一个元素是程序本身路径,读取参数
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]

e、shutil

  高级的 文件、文件夹、压缩包 处理模块

  1、shutil.copyfileobj(fsrc, fdst[, length])
  将文件内容拷贝到另一个文件中,可以部分内容

  

import shutil
f1 = open("本节笔记",encoding="utf-8")
f2 = open("笔记2",encoding="utf-8")
shutil.copyfileobj(f1,f2)


2、shutil.copyfile(src, dst)
  拷贝文件

shuffle.copyfile("biji2","biji13")
3、shutil.copymode(src, dst)
  仅拷贝权限。内容、组、用户均不变
def copymode(src, dst):
"""Copy mode bits from src to dst"""
if hasattr(os, 'chmod'):
st = os.stat(src)
mode = stat.S_IMODE(st.st_mode)
os.chmod(dst, mode)
4、shutil.copystat(src, dst)
  拷贝状态的信息,包括:mode bits, atime, mtime, flags(要求拷贝的文件必须存在)

  

  修改了修改时间,和访问时间

  5、shutil.copy(src, dst)
  拷贝文件和权限
def copy(src, dst):
"""Copy data and mode bits ("cp src dst").

The destination may be a directory.

"""
if os.path.isdir(dst):
dst = os.path.join(dst, os.path.basename(src))
copyfile(src, dst)
copymode(src, dst)
6、shutil.copy2(src, dst)
  拷贝文件和状态信息
def copy2(src, dst):
"""Copy data and all stat info ("cp -p src dst").

The destination may be a directory.

"""
if os.path.isdir(dst):
dst = os.path.join(dst, os.path.basename(src))
copyfile(src, dst)
copystat(src, dst)
7、shutil.ignore_patterns(*patterns)
   shutil.copytree(src, dst, symlinks=False, ignore=None)
  递归的去拷贝文件

  例如:copytree(source, destination, ignore=ignore_patterns('*.pyc', 'tmp*'))

  shutil.copytree("test4","new_test4")

  8、 shutil.rmtree(path[, ignore_errors[, onerror]])
  递归的去删除文件

  shutil.rmtree("new_test4")

  9、shutil.move(src, dst)
  递归的去移动文件

10、shutil.make_archive(base_name, format,...)

  创建压缩包并返回文件路径,例如:zip、tar

  base_name: 压缩包的文件名,也可以是压缩包的路径。只是文件名时,则保存至当前目录,否则保存至指定路径,
    如:www =>保存至当前路径
    如:/Users/wupeiqi/www =>保存至/Users/wupeiqi/

  format: 压缩包种类,“zip”, “tar”, “bztar”,“gztar”

  root_dir: 要压缩的文件夹路径(默认当前目录)

  owner: 用户,默认当前用户

  group: 组,默认当前组

  logger: 用于记录日志,通常是logging.Logger对象

#将 /Users/wupeiqi/Downloads/test 下的文件打包放置当前程序目录
import shutil
ret = shutil.make_archive("wwwwwwwwww", 'gztar', root_dir='/Users/wupeiqi/Downloads/test')
#将 /Users/wupeiqi/Downloads/test 下的文件打包放置 /Users/wupeiqi/目录
import shutil
ret = shutil.make_archive("/Users/wupeiqi/wwwwwwwwww", 'gztar', root_dir='/Users/wupeiqi/Downloads/test')

 shutil 对压缩包的处理是调用 ZipFile 和 TarFile 两个模块来进行的,详细:

  ①、zipfile
import zipfile
# 压缩
z = zipfile.ZipFile('laxi.zip', 'w')
z.write('a.log')
z.write('data.data')
z.close()
# 解压
z = zipfile.ZipFile('laxi.zip', 'r')
z.extractall()
z.close()

②、tarfile
import tarfile
# 压缩
tar = tarfile.open('your.tar','w')
tar.add('/Users/wupeiqi/PycharmProjects/bbs2.zip', arcname='bbs2.zip')
tar.add('/Users/wupeiqi/PycharmProjects/cmdb.zip', arcname='cmdb.zip')
tar.close()
# 解压
tar = tarfile.open('your.tar','r')
tar.extractall() # 可设置解压地址
tar.close()
 ③、ZipFile
class ZipFile(object):
""" Class with methods to open, read, write, close, list zip files.

z = ZipFile(file, mode="r", compression=ZIP_STORED, allowZip64=False)

file: Either the path to the file, or a file-like object.
If it is a path, the file will be opened and closed by ZipFile.
mode: The mode can be either read "r", write "w" or append "a".
compression: ZIP_STORED (no compression) or ZIP_DEFLATED (requires zlib).
allowZip64: if True ZipFile will create files with ZIP64 extensions when
needed, otherwise it will raise an exception when this would
be necessary.

"""

fp = None # Set here since __del__ checks it

def __init__(self, file, mode="r", compression=ZIP_STORED, allowZip64=False):
"""Open the ZIP file with mode read "r", write "w" or append "a"."""
if mode not in ("r", "w", "a"):
raise RuntimeError('ZipFile() requires mode "r", "w", or "a"')

if compression == ZIP_STORED:
pass
elif compression == ZIP_DEFLATED:
if not zlib:
raise RuntimeError,\
"Compression requires the (missing) zlib module"
else:
raise RuntimeError, "That compression method is not supported"

self._allowZip64 = allowZip64
self._didModify = False
self.debug = 0 # Level of printing: 0 through 3
self.NameToInfo = {} # Find file info given name
self.filelist = [] # List of ZipInfo instances for archive
self.compression = compression # Method of compression
self.mode = key = mode.replace('b', '')[0]
self.pwd = None
self._comment = ''

# Check if we were passed a file-like object
if isinstance(file, basestring):
self._filePassed = 0
self.filename = file
modeDict = {'r' : 'rb', 'w': 'wb', 'a' : 'r+b'}
try:
self.fp = open(file, modeDict[mode])
except IOError:
if mode == 'a':
mode = key = 'w'
self.fp = open(file, modeDict[mode])
else:
raise
else:
self._filePassed = 1
self.fp = file
self.filename = getattr(file, 'name', None)

try:
if key == 'r':
self._RealGetContents()
elif key == 'w':
# set the modified flag so central directory gets written
# even if no files are added to the archive
self._didModify = True
elif key == 'a':
try:
# See if file is a zip file
self._RealGetContents()
# seek to start of directory and overwrite
self.fp.seek(self.start_dir, 0)
except BadZipfile:
# file is not a zip file, just append
self.fp.seek(0, 2)

# set the modified flag so central directory gets written
# even if no files are added to the archive
self._didModify = True
else:
raise RuntimeError('Mode must be "r", "w" or "a"')
except:
fp = self.fp
self.fp = None
if not self._filePassed:
fp.close()
raise

def __enter__(self):
return self

def __exit__(self, type, value, traceback):
self.close()

def _RealGetContents(self):
"""Read in the table of contents for the ZIP file."""
fp = self.fp
try:
endrec = _EndRecData(fp)
except IOError:
raise BadZipfile("File is not a zip file")
if not endrec:
raise BadZipfile, "File is not a zip file"
if self.debug > 1:
print endrec
size_cd = endrec[_ECD_SIZE] # bytes in central directory
offset_cd = endrec[_ECD_OFFSET] # offset of central directory
self._comment = endrec[_ECD_COMMENT] # archive comment

# "concat" is zero, unless zip was concatenated to another file
concat = endrec[_ECD_LOCATION] - size_cd - offset_cd
if endrec[_ECD_SIGNATURE] == stringEndArchive64:
# If Zip64 extension structures are present, account for them
concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator)

if self.debug > 2:
inferred = concat + offset_cd
print "given, inferred, offset", offset_cd, inferred, concat
# self.start_dir: Position of start of central directory
self.start_dir = offset_cd + concat
fp.seek(self.start_dir, 0)
data = fp.read(size_cd)
fp = cStringIO.StringIO(data)
total = 0
while total < size_cd:
centdir = fp.read(sizeCentralDir)
if len(centdir) != sizeCentralDir:
raise BadZipfile("Truncated central directory")
centdir = struct.unpack(structCentralDir, centdir)
if centdir[_CD_SIGNATURE] != stringCentralDir:
raise BadZipfile("Bad magic number for central directory")
if self.debug > 2:
print centdir
filename = fp.read(centdir[_CD_FILENAME_LENGTH])
# Create ZipInfo instance to store file information
x = ZipInfo(filename)
x.extra = fp.read(centdir[_CD_EXTRA_FIELD_LENGTH])
x.comment = fp.read(centdir[_CD_COMMENT_LENGTH])
x.header_offset = centdir[_CD_LOCAL_HEADER_OFFSET]
(x.create_version, x.create_system, x.extract_version, x.reserved,
x.flag_bits, x.compress_type, t, d,
x.CRC, x.compress_size, x.file_size) = centdir[1:12]
x.volume, x.internal_attr, x.external_attr = centdir[15:18]
# Convert date/time code to (year, month, day, hour, min, sec)
x._raw_time = t
x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F,
t>>11, (t>>5)&0x3F, (t&0x1F) * 2 )

x._decodeExtra()
x.header_offset = x.header_offset + concat
x.filename = x._decodeFilename()
self.filelist.append(x)
self.NameToInfo[x.filename] = x

# update total bytes read from central directory
total = (total + sizeCentralDir + centdir[_CD_FILENAME_LENGTH]
+ centdir[_CD_EXTRA_FIELD_LENGTH]
+ centdir[_CD_COMMENT_LENGTH])

if self.debug > 2:
print "total", total


def namelist(self):
"""Return a list of file names in the archive."""
l = []
for data in self.filelist:
l.append(data.filename)
return l

def infolist(self):
"""Return a list of class ZipInfo instances for files in the
archive."""
return self.filelist

def printdir(self):
"""Print a table of contents for the zip file."""
print "%-46s %19s %12s" % ("File Name", "Modified ", "Size")
for zinfo in self.filelist:
date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size)

def testzip(self):
"""Read all the files and check the CRC."""
chunk_size = 2 ** 20
for zinfo in self.filelist:
try:
# Read by chunks, to avoid an OverflowError or a
# MemoryError with very large embedded files.
with self.open(zinfo.filename, "r") as f:
while f.read(chunk_size): # Check CRC-32
pass
except BadZipfile:
return zinfo.filename

def getinfo(self, name):
"""Return the instance of ZipInfo given 'name'."""
info = self.NameToInfo.get(name)
if info is None:
raise KeyError(
'There is no item named %r in the archive' % name)

return info

def setpassword(self, pwd):
"""Set default password for encrypted files."""
self.pwd = pwd

@property
def comment(self):
"""The comment text associated with the ZIP file."""
return self._comment

@comment.setter
def comment(self, comment):
# check for valid comment length
if len(comment) > ZIP_MAX_COMMENT:
import warnings
warnings.warn('Archive comment is too long; truncating to %d bytes'
% ZIP_MAX_COMMENT, stacklevel=2)
comment = comment[:ZIP_MAX_COMMENT]
self._comment = comment
self._didModify = True

def read(self, name, pwd=None):
"""Return file bytes (as a string) for name."""
return self.open(name, "r", pwd).read()

def open(self, name, mode="r", pwd=None):
"""Return file-like object for 'name'."""
if mode not in ("r", "U", "rU"):
raise RuntimeError, 'open() requires mode "r", "U", or "rU"'
if not self.fp:
raise RuntimeError, \
"Attempt to read ZIP archive that was already closed"

# Only open a new file for instances where we were not
# given a file object in the constructor
if self._filePassed:
zef_file = self.fp
should_close = False
else:
zef_file = open(self.filename, 'rb')
should_close = True

try:
# Make sure we have an info object
if isinstance(name, ZipInfo):
# 'name' is already an info object
zinfo = name
else:
# Get info object for name
zinfo = self.getinfo(name)

zef_file.seek(zinfo.header_offset, 0)

# Skip the file header:
fheader = zef_file.read(sizeFileHeader)
if len(fheader) != sizeFileHeader:
raise BadZipfile("Truncated file header")
fheader = struct.unpack(structFileHeader, fheader)
if fheader[_FH_SIGNATURE] != stringFileHeader:
raise BadZipfile("Bad magic number for file header")

fname = zef_file.read(fheader[_FH_FILENAME_LENGTH])
if fheader[_FH_EXTRA_FIELD_LENGTH]:
zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])

if fname != zinfo.orig_filename:
raise BadZipfile, \
'File name in directory "%s" and header "%s" differ.' % (
zinfo.orig_filename, fname)

# check for encrypted flag & handle password
is_encrypted = zinfo.flag_bits & 0x1
zd = None
if is_encrypted:
if not pwd:
pwd = self.pwd
if not pwd:
raise RuntimeError, "File %s is encrypted, " \
"password required for extraction" % name

zd = _ZipDecrypter(pwd)
# The first 12 bytes in the cypher stream is an encryption header
# used to strengthen the algorithm. The first 11 bytes are
# completely random, while the 12th contains the MSB of the CRC,
# or the MSB of the file time depending on the header type
# and is used to check the correctness of the password.
bytes = zef_file.read(12)
h = map(zd, bytes[0:12])
if zinfo.flag_bits & 0x8:
# compare against the file type from extended local headers
check_byte = (zinfo._raw_time >> 8) & 0xff
else:
# compare against the CRC otherwise
check_byte = (zinfo.CRC >> 24) & 0xff
if ord(h[11]) != check_byte:
raise RuntimeError("Bad password for file", name)

return ZipExtFile(zef_file, mode, zinfo, zd,
close_fileobj=should_close)
except:
if should_close:
zef_file.close()
raise

def extract(self, member, path=None, pwd=None):
"""Extract a member from the archive to the current working directory,
using its full name. Its file information is extracted as accurately
as possible. `member' may be a filename or a ZipInfo object. You can
specify a different directory using `path'.
"""
if not isinstance(member, ZipInfo):
member = self.getinfo(member)

if path is None:
path = os.getcwd()

return self._extract_member(member, path, pwd)

def extractall(self, path=None, members=None, pwd=None):
"""Extract all members from the archive to the current working
directory. `path' specifies a different directory to extract to.
`members' is optional and must be a subset of the list returned
by namelist().
"""
if members is None:
members = self.namelist()

for zipinfo in members:
self.extract(zipinfo, path, pwd)

def _extract_member(self, member, targetpath, pwd):
"""Extract the ZipInfo object 'member' to a physical
file on the path targetpath.
"""
# build the destination pathname, replacing
# forward slashes to platform specific separators.
arcname = member.filename.replace('/', os.path.sep)

if os.path.altsep:
arcname = arcname.replace(os.path.altsep, os.path.sep)
# interpret absolute pathname as relative, remove drive letter or
# UNC path, redundant separators, "." and ".." components.
arcname = os.path.splitdrive(arcname)[1]
arcname = os.path.sep.join(x for x in arcname.split(os.path.sep)
if x not in ('', os.path.curdir, os.path.pardir))
if os.path.sep == '\\':
# filter illegal characters on Windows
illegal = ':<>|"?*'
if isinstance(arcname, unicode):
table = {ord(c): ord('_') for c in illegal}
else:
table = string.maketrans(illegal, '_' * len(illegal))
arcname = arcname.translate(table)
# remove trailing dots
arcname = (x.rstrip('.') for x in arcname.split(os.path.sep))
arcname = os.path.sep.join(x for x in arcname if x)

targetpath = os.path.join(targetpath, arcname)
targetpath = os.path.normpath(targetpath)

# Create all upper directories if necessary.
upperdirs = os.path.dirname(targetpath)
if upperdirs and not os.path.exists(upperdirs):
os.makedirs(upperdirs)

if member.filename[-1] == '/':
if not os.path.isdir(targetpath):
os.mkdir(targetpath)
return targetpath

with self.open(member, pwd=pwd) as source, \
file(targetpath, "wb") as target:
shutil.copyfileobj(source, target)

return targetpath

def _writecheck(self, zinfo):
"""Check for errors before writing a file to the archive."""
if zinfo.filename in self.NameToInfo:
import warnings
warnings.warn('Duplicate name: %r' % zinfo.filename, stacklevel=3)
if self.mode not in ("w", "a"):
raise RuntimeError, 'write() requires mode "w" or "a"'
if not self.fp:
raise RuntimeError, \
"Attempt to write ZIP archive that was already closed"
if zinfo.compress_type == ZIP_DEFLATED and not zlib:
raise RuntimeError, \
"Compression requires the (missing) zlib module"
if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED):
raise RuntimeError, \
"That compression method is not supported"
if not self._allowZip64:
requires_zip64 = None
if len(self.filelist) >= ZIP_FILECOUNT_LIMIT:
requires_zip64 = "Files count"
elif zinfo.file_size > ZIP64_LIMIT:
requires_zip64 = "Filesize"
elif zinfo.header_offset > ZIP64_LIMIT:
requires_zip64 = "Zipfile size"
if requires_zip64:
raise LargeZipFile(requires_zip64 +
" would require ZIP64 extensions")

def write(self, filename, arcname=None, compress_type=None):
"""Put the bytes from filename into the archive under the name
arcname."""
if not self.fp:
raise RuntimeError(
"Attempt to write to ZIP archive that was already closed")

st = os.stat(filename)
isdir = stat.S_ISDIR(st.st_mode)
mtime = time.localtime(st.st_mtime)
date_time = mtime[0:6]
# Create ZipInfo instance to store file information
if arcname is None:
arcname = filename
arcname = os.path.normpath(os.path.splitdrive(arcname)[1])
while arcname[0] in (os.sep, os.altsep):
arcname = arcname[1:]
if isdir:
arcname += '/'
zinfo = ZipInfo(arcname, date_time)
zinfo.external_attr = (st[0] & 0xFFFF) << 16L # Unix attributes
if compress_type is None:
zinfo.compress_type = self.compression
else:
zinfo.compress_type = compress_type

zinfo.file_size = st.st_size
zinfo.flag_bits = 0x00
zinfo.header_offset = self.fp.tell() # Start of header bytes

self._writecheck(zinfo)
self._didModify = True

if isdir:
zinfo.file_size = 0
zinfo.compress_size = 0
zinfo.CRC = 0
zinfo.external_attr |= 0x10 # MS-DOS directory flag
self.filelist.append(zinfo)
self.NameToInfo[zinfo.filename] = zinfo
self.fp.write(zinfo.FileHeader(False))
return

with open(filename, "rb") as fp:
# Must overwrite CRC and sizes with correct data later
zinfo.CRC = CRC = 0
zinfo.compress_size = compress_size = 0
# Compressed size can be larger than uncompressed size
zip64 = self._allowZip64 and \
zinfo.file_size * 1.05 > ZIP64_LIMIT
self.fp.write(zinfo.FileHeader(zip64))
if zinfo.compress_type == ZIP_DEFLATED:
cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
zlib.DEFLATED, -15)
else:
cmpr = None
file_size = 0
while 1:
buf = fp.read(1024 * 8)
if not buf:
break
file_size = file_size + len(buf)
CRC = crc32(buf, CRC) & 0xffffffff
if cmpr:
buf = cmpr.compress(buf)
compress_size = compress_size + len(buf)
self.fp.write(buf)
if cmpr:
buf = cmpr.flush()
compress_size = compress_size + len(buf)
self.fp.write(buf)
zinfo.compress_size = compress_size
else:
zinfo.compress_size = file_size
zinfo.CRC = CRC
zinfo.file_size = file_size
if not zip64 and self._allowZip64:
if file_size > ZIP64_LIMIT:
raise RuntimeError('File size has increased during compressing')
if compress_size > ZIP64_LIMIT:
raise RuntimeError('Compressed size larger than uncompressed size')
# Seek backwards and write file header (which will now include
# correct CRC and file sizes)
position = self.fp.tell() # Preserve current position in file
self.fp.seek(zinfo.header_offset, 0)
self.fp.write(zinfo.FileHeader(zip64))
self.fp.seek(position, 0)
self.filelist.append(zinfo)
self.NameToInfo[zinfo.filename] = zinfo

def writestr(self, zinfo_or_arcname, bytes, compress_type=None):
"""Write a file into the archive. The contents is the string
'bytes'. 'zinfo_or_arcname' is either a ZipInfo instance or
the name of the file in the archive."""
if not isinstance(zinfo_or_arcname, ZipInfo):
zinfo = ZipInfo(filename=zinfo_or_arcname,
date_time=time.localtime(time.time())[:6])

zinfo.compress_type = self.compression
if zinfo.filename[-1] == '/':
zinfo.external_attr = 0o40775 << 16 # drwxrwxr-x
zinfo.external_attr |= 0x10 # MS-DOS directory flag
else:
zinfo.external_attr = 0o600 << 16 # ?rw-------
else:
zinfo = zinfo_or_arcname

if not self.fp:
raise RuntimeError(
"Attempt to write to ZIP archive that was already closed")

if compress_type is not None:
zinfo.compress_type = compress_type

zinfo.file_size = len(bytes) # Uncompressed size
zinfo.header_offset = self.fp.tell() # Start of header bytes
self._writecheck(zinfo)
self._didModify = True
zinfo.CRC = crc32(bytes) & 0xffffffff # CRC-32 checksum
if zinfo.compress_type == ZIP_DEFLATED:
co = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
zlib.DEFLATED, -15)
bytes = co.compress(bytes) + co.flush()
zinfo.compress_size = len(bytes) # Compressed size
else:
zinfo.compress_size = zinfo.file_size
zip64 = zinfo.file_size > ZIP64_LIMIT or \
zinfo.compress_size > ZIP64_LIMIT
if zip64 and not self._allowZip64:
raise LargeZipFile("Filesize would require ZIP64 extensions")
self.fp.write(zinfo.FileHeader(zip64))
self.fp.write(bytes)
if zinfo.flag_bits & 0x08:
# Write CRC and file sizes after the file data
fmt = '<LQQ' if zip64 else '<LLL'
self.fp.write(struct.pack(fmt, zinfo.CRC, zinfo.compress_size,
zinfo.file_size))
self.fp.flush()
self.filelist.append(zinfo)
self.NameToInfo[zinfo.filename] = zinfo

def __del__(self):
"""Call the "close()" method in case the user forgot."""
self.close()

def close(self):
"""Close the file, and for mode "w" and "a" write the ending
records."""
if self.fp is None:
return

try:
if self.mode in ("w", "a") and self._didModify: # write ending records
pos1 = self.fp.tell()
for zinfo in self.filelist: # write central directory
dt = zinfo.date_time
dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
extra = []
if zinfo.file_size > ZIP64_LIMIT \
or zinfo.compress_size > ZIP64_LIMIT:
extra.append(zinfo.file_size)
extra.append(zinfo.compress_size)
file_size = 0xffffffff
compress_size = 0xffffffff
else:
file_size = zinfo.file_size
compress_size = zinfo.compress_size

if zinfo.header_offset > ZIP64_LIMIT:
extra.append(zinfo.header_offset)
header_offset = 0xffffffffL
else:
header_offset = zinfo.header_offset

extra_data = zinfo.extra
if extra:
# Append a ZIP64 field to the extra's
extra_data = struct.pack(
'<HH' + 'Q'*len(extra),
1, 8*len(extra), *extra) + extra_data

extract_version = max(45, zinfo.extract_version)
create_version = max(45, zinfo.create_version)
else:
extract_version = zinfo.extract_version
create_version = zinfo.create_version

try:
filename, flag_bits = zinfo._encodeFilenameFlags()
centdir = struct.pack(structCentralDir,
stringCentralDir, create_version,
zinfo.create_system, extract_version, zinfo.reserved,
flag_bits, zinfo.compress_type, dostime, dosdate,
zinfo.CRC, compress_size, file_size,
len(filename), len(extra_data), len(zinfo.comment),
0, zinfo.internal_attr, zinfo.external_attr,
header_offset)
except DeprecationWarning:
print >>sys.stderr, (structCentralDir,
stringCentralDir, create_version,
zinfo.create_system, extract_version, zinfo.reserved,
zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
zinfo.CRC, compress_size, file_size,
len(zinfo.filename), len(extra_data), len(zinfo.comment),
0, zinfo.internal_attr, zinfo.external_attr,
header_offset)
raise
self.fp.write(centdir)
self.fp.write(filename)
self.fp.write(extra_data)
self.fp.write(zinfo.comment)

pos2 = self.fp.tell()
# Write end-of-zip-archive record
centDirCount = len(self.filelist)
centDirSize = pos2 - pos1
centDirOffset = pos1
requires_zip64 = None
if centDirCount > ZIP_FILECOUNT_LIMIT:
requires_zip64 = "Files count"
elif centDirOffset > ZIP64_LIMIT:
requires_zip64 = "Central directory offset"
elif centDirSize > ZIP64_LIMIT:
requires_zip64 = "Central directory size"
if requires_zip64:
# Need to write the ZIP64 end-of-archive records
if not self._allowZip64:
raise LargeZipFile(requires_zip64 +
" would require ZIP64 extensions")
zip64endrec = struct.pack(
structEndArchive64, stringEndArchive64,
44, 45, 45, 0, 0, centDirCount, centDirCount,
centDirSize, centDirOffset)
self.fp.write(zip64endrec)

zip64locrec = struct.pack(
structEndArchive64Locator,
stringEndArchive64Locator, 0, pos2, 1)
self.fp.write(zip64locrec)
centDirCount = min(centDirCount, 0xFFFF)
centDirSize = min(centDirSize, 0xFFFFFFFF)
centDirOffset = min(centDirOffset, 0xFFFFFFFF)

endrec = struct.pack(structEndArchive, stringEndArchive,
0, 0, centDirCount, centDirCount,
centDirSize, centDirOffset, len(self._comment))
self.fp.write(endrec)
self.fp.write(self._comment)
self.fp.flush()
finally:
fp = self.fp
self.fp = None
if not self._filePassed:
fp.close()

  ④、TarFile

class TarFile(object):
"""The TarFile Class provides an interface to tar archives.
"""

debug = 0 # May be set from 0 (no msgs) to 3 (all msgs)

dereference = False # If true, add content of linked file to the
# tar file, else the link.

ignore_zeros = False # If true, skips empty or invalid blocks and
# continues processing.

errorlevel = 1 # If 0, fatal errors only appear in debug
# messages (if debug >= 0). If > 0, errors
# are passed to the caller as exceptions.

format = DEFAULT_FORMAT # The format to use when creating an archive.

encoding = ENCODING # Encoding for 8-bit character strings.

errors = None # Error handler for unicode conversion.

tarinfo = TarInfo # The default TarInfo class to use.

fileobject = ExFileObject # The default ExFileObject class to use.

def __init__(self, name=None, mode="r", fileobj=None, format=None,
tarinfo=None, dereference=None, ignore_zeros=None, encoding=None,
errors=None, pax_headers=None, debug=None, errorlevel=None):
"""Open an (uncompressed) tar archive `name'. `mode' is either 'r' to
read from an existing archive, 'a' to append data to an existing
file or 'w' to create a new file overwriting an existing one. `mode'
defaults to 'r'.
If `fileobj' is given, it is used for reading or writing data. If it
can be determined, `mode' is overridden by `fileobj's mode.
`fileobj' is not closed, when TarFile is closed.
"""
modes = {"r": "rb", "a": "r+b", "w": "wb"}
if mode not in modes:
raise ValueError("mode must be 'r', 'a' or 'w'")
self.mode = mode
self._mode = modes[mode]

if not fileobj:
if self.mode == "a" and not os.path.exists(name):
# Create nonexistent files in append mode.
self.mode = "w"
self._mode = "wb"
fileobj = bltn_open(name, self._mode)
self._extfileobj = False
else:
if name is None and hasattr(fileobj, "name"):
name = fileobj.name
if hasattr(fileobj, "mode"):
self._mode = fileobj.mode
self._extfileobj = True
self.name = os.path.abspath(name) if name else None
self.fileobj = fileobj

# Init attributes.
if format is not None:
self.format = format
if tarinfo is not None:
self.tarinfo = tarinfo
if dereference is not None:
self.dereference = dereference
if ignore_zeros is not None:
self.ignore_zeros = ignore_zeros
if encoding is not None:
self.encoding = encoding

if errors is not None:
self.errors = errors
elif mode == "r":
self.errors = "utf-8"
else:
self.errors = "strict"

if pax_headers is not None and self.format == PAX_FORMAT:
self.pax_headers = pax_headers
else:
self.pax_headers = {}

if debug is not None:
self.debug = debug
if errorlevel is not None:
self.errorlevel = errorlevel

# Init datastructures.
self.closed = False
self.members = [] # list of members as TarInfo objects
self._loaded = False # flag if all members have been read
self.offset = self.fileobj.tell()
# current position in the archive file
self.inodes = {} # dictionary caching the inodes of
# archive members already added

try:
if self.mode == "r":
self.firstmember = None
self.firstmember = self.next()

if self.mode == "a":
# Move to the end of the archive,
# before the first empty block.
while True:
self.fileobj.seek(self.offset)
try:
tarinfo = self.tarinfo.fromtarfile(self)
self.members.append(tarinfo)
except EOFHeaderError:
self.fileobj.seek(self.offset)
break
except HeaderError, e:
raise ReadError(str(e))

if self.mode in "aw":
self._loaded = True

if self.pax_headers:
buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy())
self.fileobj.write(buf)
self.offset += len(buf)
except:
if not self._extfileobj:
self.fileobj.close()
self.closed = True
raise

def _getposix(self):
return self.format == USTAR_FORMAT
def _setposix(self, value):
import warnings
warnings.warn("use the format attribute instead", DeprecationWarning,
2)
if value:
self.format = USTAR_FORMAT
else:
self.format = GNU_FORMAT
posix = property(_getposix, _setposix)

#--------------------------------------------------------------------------
# Below are the classmethods which act as alternate constructors to the
# TarFile class. The open() method is the only one that is needed for
# public use; it is the "super"-constructor and is able to select an
# adequate "sub"-constructor for a particular compression using the mapping
# from OPEN_METH.
#
# This concept allows one to subclass TarFile without losing the comfort of
# the super-constructor. A sub-constructor is registered and made available
# by adding it to the mapping in OPEN_METH.

@classmethod
def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs):
"""Open a tar archive for reading, writing or appending. Return
an appropriate TarFile class.

mode:
'r' or 'r:*' open for reading with transparent compression
'r:' open for reading exclusively uncompressed
'r:gz' open for reading with gzip compression
'r:bz2' open for reading with bzip2 compression
'a' or 'a:' open for appending, creating the file if necessary
'w' or 'w:' open for writing without compression
'w:gz' open for writing with gzip compression
'w:bz2' open for writing with bzip2 compression

'r|*' open a stream of tar blocks with transparent compression
'r|' open an uncompressed stream of tar blocks for reading
'r|gz' open a gzip compressed stream of tar blocks
'r|bz2' open a bzip2 compressed stream of tar blocks
'w|' open an uncompressed stream for writing
'w|gz' open a gzip compressed stream for writing
'w|bz2' open a bzip2 compressed stream for writing
"""

if not name and not fileobj:
raise ValueError("nothing to open")

if mode in ("r", "r:*"):
# Find out which *open() is appropriate for opening the file.
for comptype in cls.OPEN_METH:
func = getattr(cls, cls.OPEN_METH[comptype])
if fileobj is not None:
saved_pos = fileobj.tell()
try:
return func(name, "r", fileobj, **kwargs)
except (ReadError, CompressionError), e:
if fileobj is not None:
fileobj.seek(saved_pos)
continue
raise ReadError("file could not be opened successfully")

elif ":" in mode:
filemode, comptype = mode.split(":", 1)
filemode = filemode or "r"
comptype = comptype or "tar"

# Select the *open() function according to
# given compression.
if comptype in cls.OPEN_METH:
func = getattr(cls, cls.OPEN_METH[comptype])
else:
raise CompressionError("unknown compression type %r" % comptype)
return func(name, filemode, fileobj, **kwargs)

elif "|" in mode:
filemode, comptype = mode.split("|", 1)
filemode = filemode or "r"
comptype = comptype or "tar"

if filemode not in ("r", "w"):
raise ValueError("mode must be 'r' or 'w'")

stream = _Stream(name, filemode, comptype, fileobj, bufsize)
try:
t = cls(name, filemode, stream, **kwargs)
except:
stream.close()
raise
t._extfileobj = False
return t

elif mode in ("a", "w"):
return cls.taropen(name, mode, fileobj, **kwargs)

raise ValueError("undiscernible mode")

@classmethod
def taropen(cls, name, mode="r", fileobj=None, **kwargs):
"""Open uncompressed tar archive name for reading or writing.
"""
if mode not in ("r", "a", "w"):
raise ValueError("mode must be 'r', 'a' or 'w'")
return cls(name, mode, fileobj, **kwargs)

@classmethod
def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
"""Open gzip compressed tar archive name for reading or writing.
Appending is not allowed.
"""
if mode not in ("r", "w"):
raise ValueError("mode must be 'r' or 'w'")

try:
import gzip
gzip.GzipFile
except (ImportError, AttributeError):
raise CompressionError("gzip module is not available")

try:
fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj)
except OSError:
if fileobj is not None and mode == 'r':
raise ReadError("not a gzip file")
raise

try:
t = cls.taropen(name, mode, fileobj, **kwargs)
except IOError:
fileobj.close()
if mode == 'r':
raise ReadError("not a gzip file")
raise
except:
fileobj.close()
raise
t._extfileobj = False
return t

@classmethod
def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
"""Open bzip2 compressed tar archive name for reading or writing.
Appending is not allowed.
"""
if mode not in ("r", "w"):
raise ValueError("mode must be 'r' or 'w'.")

try:
import bz2
except ImportError:
raise CompressionError("bz2 module is not available")

if fileobj is not None:
fileobj = _BZ2Proxy(fileobj, mode)
else:
fileobj = bz2.BZ2File(name, mode, compresslevel=compresslevel)

try:
t = cls.taropen(name, mode, fileobj, **kwargs)
except (IOError, EOFError):
fileobj.close()
if mode == 'r':
raise ReadError("not a bzip2 file")
raise
except:
fileobj.close()
raise
t._extfileobj = False
return t

# All *open() methods are registered here.
OPEN_METH = {
"tar": "taropen", # uncompressed tar
"gz": "gzopen", # gzip compressed tar
"bz2": "bz2open" # bzip2 compressed tar
}

#--------------------------------------------------------------------------
# The public methods which TarFile provides:

def close(self):
"""Close the TarFile. In write-mode, two finishing zero blocks are
appended to the archive.
"""
if self.closed:
return

if self.mode in "aw":
self.fileobj.write(NUL * (BLOCKSIZE * 2))
self.offset += (BLOCKSIZE * 2)
# fill up the end with zero-blocks
# (like option -b20 for tar does)
blocks, remainder = divmod(self.offset, RECORDSIZE)
if remainder > 0:
self.fileobj.write(NUL * (RECORDSIZE - remainder))

if not self._extfileobj:
self.fileobj.close()
self.closed = True

def getmember(self, name):
"""Return a TarInfo object for member `name'. If `name' can not be
found in the archive, KeyError is raised. If a member occurs more
than once in the archive, its last occurrence is assumed to be the
most up-to-date version.
"""
tarinfo = self._getmember(name)
if tarinfo is None:
raise KeyError("filename %r not found" % name)
return tarinfo

def getmembers(self):
"""Return the members of the archive as a list of TarInfo objects. The
list has the same order as the members in the archive.
"""
self._check()
if not self._loaded: # if we want to obtain a list of
self._load() # all members, we first have to
# scan the whole archive.
return self.members

def getnames(self):
"""Return the members of the archive as a list of their names. It has
the same order as the list returned by getmembers().
"""
return [tarinfo.name for tarinfo in self.getmembers()]

def gettarinfo(self, name=None, arcname=None, fileobj=None):
"""Create a TarInfo object for either the file `name' or the file
object `fileobj' (using os.fstat on its file descriptor). You can
modify some of the TarInfo's attributes before you add it using
addfile(). If given, `arcname' specifies an alternative name for the
file in the archive.
"""
self._check("aw")

# When fileobj is given, replace name by
# fileobj's real name.
if fileobj is not None:
name = fileobj.name

# Building the name of the member in the archive.
# Backward slashes are converted to forward slashes,
# Absolute paths are turned to relative paths.
if arcname is None:
arcname = name
drv, arcname = os.path.splitdrive(arcname)
arcname = arcname.replace(os.sep, "/")
arcname = arcname.lstrip("/")

# Now, fill the TarInfo object with
# information specific for the file.
tarinfo = self.tarinfo()
tarinfo.tarfile = self

# Use os.stat or os.lstat, depending on platform
# and if symlinks shall be resolved.
if fileobj is None:
if hasattr(os, "lstat") and not self.dereference:
statres = os.lstat(name)
else:
statres = os.stat(name)
else:
statres = os.fstat(fileobj.fileno())
linkname = ""

stmd = statres.st_mode
if stat.S_ISREG(stmd):
inode = (statres.st_ino, statres.st_dev)
if not self.dereference and statres.st_nlink > 1 and \
inode in self.inodes and arcname != self.inodes[inode]:
# Is it a hardlink to an already
# archived file?
type = LNKTYPE
linkname = self.inodes[inode]
else:
# The inode is added only if its valid.
# For win32 it is always 0.
type = REGTYPE
if inode[0]:
self.inodes[inode] = arcname
elif stat.S_ISDIR(stmd):
type = DIRTYPE
elif stat.S_ISFIFO(stmd):
type = FIFOTYPE
elif stat.S_ISLNK(stmd):
type = SYMTYPE
linkname = os.readlink(name)
elif stat.S_ISCHR(stmd):
type = CHRTYPE
elif stat.S_ISBLK(stmd):
type = BLKTYPE
else:
return None

# Fill the TarInfo object with all
# information we can get.
tarinfo.name = arcname
tarinfo.mode = stmd
tarinfo.uid = statres.st_uid
tarinfo.gid = statres.st_gid
if type == REGTYPE:
tarinfo.size = statres.st_size
else:
tarinfo.size = 0L
tarinfo.mtime = statres.st_mtime
tarinfo.type = type
tarinfo.linkname = linkname
if pwd:
try:
tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0]
except KeyError:
pass
if grp:
try:
tarinfo.gname = grp.getgrgid(tarinfo.gid)[0]
except KeyError:
pass

if type in (CHRTYPE, BLKTYPE):
if hasattr(os, "major") and hasattr(os, "minor"):
tarinfo.devmajor = os.major(statres.st_rdev)
tarinfo.devminor = os.minor(statres.st_rdev)
return tarinfo

def list(self, verbose=True):
"""Print a table of contents to sys.stdout. If `verbose' is False, only
the names of the members are printed. If it is True, an `ls -l'-like
output is produced.
"""
self._check()

for tarinfo in self:
if verbose:
print filemode(tarinfo.mode),
print "%s/%s" % (tarinfo.uname or tarinfo.uid,
tarinfo.gname or tarinfo.gid),
if tarinfo.ischr() or tarinfo.isblk():
print "%10s" % ("%d,%d" \
% (tarinfo.devmajor, tarinfo.devminor)),
else:
print "%10d" % tarinfo.size,
print "%d-%02d-%02d %02d:%02d:%02d" \
% time.localtime(tarinfo.mtime)[:6],

print tarinfo.name + ("/" if tarinfo.isdir() else ""),

if verbose:
if tarinfo.issym():
print "->", tarinfo.linkname,
if tarinfo.islnk():
print "link to", tarinfo.linkname,
print

def add(self, name, arcname=None, recursive=True, exclude=None, filter=None):
"""Add the file `name' to the archive. `name' may be any type of file
(directory, fifo, symbolic link, etc.). If given, `arcname'
specifies an alternative name for the file in the archive.
Directories are added recursively by default. This can be avoided by
setting `recursive' to False. `exclude' is a function that should
return True for each filename to be excluded. `filter' is a function
that expects a TarInfo object arXPment and returns the changed
TarInfo object, if it returns None the TarInfo object will be
excluded from the archive.
"""
self._check("aw")

if arcname is None:
arcname = name

# Exclude pathnames.
if exclude is not None:
import warnings
warnings.warn("use the filter arXPment instead",
DeprecationWarning, 2)
if exclude(name):
self._dbg(2, "tarfile: Excluded %r" % name)
return

# Skip if somebody tries to archive the archive...
if self.name is not None and os.path.abspath(name) == self.name:
self._dbg(2, "tarfile: Skipped %r" % name)
return

self._dbg(1, name)

# Create a TarInfo object from the file.
tarinfo = self.gettarinfo(name, arcname)

if tarinfo is None:
self._dbg(1, "tarfile: Unsupported type %r" % name)
return

# Change or exclude the TarInfo object.
if filter is not None:
tarinfo = filter(tarinfo)
if tarinfo is None:
self._dbg(2, "tarfile: Excluded %r" % name)
return

# Append the tar header and data to the archive.
if tarinfo.isreg():
with bltn_open(name, "rb") as f:
self.addfile(tarinfo, f)

elif tarinfo.isdir():
self.addfile(tarinfo)
if recursive:
for f in os.listdir(name):
self.add(os.path.join(name, f), os.path.join(arcname, f),
recursive, exclude, filter)

else:
self.addfile(tarinfo)

def addfile(self, tarinfo, fileobj=None):
"""Add the TarInfo object `tarinfo' to the archive. If `fileobj' is
given, tarinfo.size bytes are read from it and added to the archive.
You can create TarInfo objects using gettarinfo().
On Windows platforms, `fileobj' should always be opened with mode
'rb' to avoid irritation about the file size.
"""
self._check("aw")

tarinfo = copy.copy(tarinfo)

buf = tarinfo.tobuf(self.format, self.encoding, self.errors)
self.fileobj.write(buf)
self.offset += len(buf)

# If there's data to follow, append it.
if fileobj is not None:
copyfileobj(fileobj, self.fileobj, tarinfo.size)
blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
if remainder > 0:
self.fileobj.write(NUL * (BLOCKSIZE - remainder))
blocks += 1
self.offset += blocks * BLOCKSIZE

self.members.append(tarinfo)

def extractall(self, path=".", members=None):
"""Extract all members from the archive to the current working
directory and set owner, modification time and permissions on
directories afterwards. `path' specifies a different directory
to extract to. `members' is optional and must be a subset of the
list returned by getmembers().
"""
directories = []

if members is None:
members = self

for tarinfo in members:
if tarinfo.isdir():
# Extract directories with a safe mode.
directories.append(tarinfo)
tarinfo = copy.copy(tarinfo)
tarinfo.mode = 0700
self.extract(tarinfo, path)

# Reverse sort directories.
directories.sort(key=operator.attrgetter('name'))
directories.reverse()

# Set correct owner, mtime and filemode on directories.
for tarinfo in directories:
dirpath = os.path.join(path, tarinfo.name)
try:
self.chown(tarinfo, dirpath)
self.utime(tarinfo, dirpath)
self.chmod(tarinfo, dirpath)
except ExtractError, e:
if self.errorlevel > 1:
raise
else:
self._dbg(1, "tarfile: %s" % e)

def extract(self, member, path=""):
"""Extract a member from the archive to the current working directory,
using its full name. Its file information is extracted as accurately
as possible. `member' may be a filename or a TarInfo object. You can
specify a different directory using `path'.
"""
self._check("r")

if isinstance(member, basestring):
tarinfo = self.getmember(member)
else:
tarinfo = member

# Prepare the link target for makelink().
if tarinfo.islnk():
tarinfo._link_target = os.path.join(path, tarinfo.linkname)

try:
self._extract_member(tarinfo, os.path.join(path, tarinfo.name))
except EnvironmentError, e:
if self.errorlevel > 0:
raise
else:
if e.filename is None:
self._dbg(1, "tarfile: %s" % e.strerror)
else:
self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename))
except ExtractError, e:
if self.errorlevel > 1:
raise
else:
self._dbg(1, "tarfile: %s" % e)

def extractfile(self, member):
"""Extract a member from the archive as a file object. `member' may be
a filename or a TarInfo object. If `member' is a reXPlar file, a
file-like object is returned. If `member' is a link, a file-like
object is constructed from the link's target. If `member' is none of
the above, None is returned.
The file-like object is read-only and provides the following
methods: read(), readline(), readlines(), seek() and tell()
"""
self._check("r")

if isinstance(member, basestring):
tarinfo = self.getmember(member)
else:
tarinfo = member

if tarinfo.isreg():
return self.fileobject(self, tarinfo)

elif tarinfo.type not in SUPPORTED_TYPES:
# If a member's type is unknown, it is treated as a
# reXPlar file.
return self.fileobject(self, tarinfo)

elif tarinfo.islnk() or tarinfo.issym():
if isinstance(self.fileobj, _Stream):
# A small but ugly workaround for the case that someone tries
# to extract a (sym)link as a file-object from a non-seekable
# stream of tar blocks.
raise StreamError("cannot extract (sym)link as file object")
else:
# A (sym)link's file object is its target's file object.
return self.extractfile(self._find_link_target(tarinfo))
else:
# If there's no data associated with the member (directory, chrdev,
# blkdev, etc.), return None instead of a file object.
return None

def _extract_member(self, tarinfo, targetpath):
"""Extract the TarInfo object tarinfo to a physical
file called targetpath.
"""
# Fetch the TarInfo object for the given name
# and build the destination pathname, replacing
# forward slashes to platform specific separators.
targetpath = targetpath.rstrip("/")
targetpath = targetpath.replace("/", os.sep)

# Create all upper directories.
upperdirs = os.path.dirname(targetpath)
if upperdirs and not os.path.exists(upperdirs):
# Create directories that are not part of the archive with
# default permissions.
os.makedirs(upperdirs)

if tarinfo.islnk() or tarinfo.issym():
self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname))
else:
self._dbg(1, tarinfo.name)

if tarinfo.isreg():
self.makefile(tarinfo, targetpath)
elif tarinfo.isdir():
self.makedir(tarinfo, targetpath)
elif tarinfo.isfifo():
self.makefifo(tarinfo, targetpath)
elif tarinfo.ischr() or tarinfo.isblk():
self.makedev(tarinfo, targetpath)
elif tarinfo.islnk() or tarinfo.issym():
self.makelink(tarinfo, targetpath)
elif tarinfo.type not in SUPPORTED_TYPES:
self.makeunknown(tarinfo, targetpath)
else:
self.makefile(tarinfo, targetpath)

self.chown(tarinfo, targetpath)
if not tarinfo.issym():
self.chmod(tarinfo, targetpath)
self.utime(tarinfo, targetpath)

#--------------------------------------------------------------------------
# Below are the different file methods. They are called via
# _extract_member() when extract() is called. They can be replaced in a
# subclass to implement other functionality.

def makedir(self, tarinfo, targetpath):
"""Make a directory called targetpath.
"""
try:
# Use a safe mode for the directory, the real mode is set
# later in _extract_member().
os.mkdir(targetpath, 0700)
except EnvironmentError, e:
if e.errno != errno.EEXIST:
raise

def makefile(self, tarinfo, targetpath):
"""Make a file called targetpath.
"""
source = self.extractfile(tarinfo)
try:
with bltn_open(targetpath, "wb") as target:
copyfileobj(source, target)
finally:
source.close()

def makeunknown(self, tarinfo, targetpath):
"""Make a file from a TarInfo object with an unknown type
at targetpath.
"""
self.makefile(tarinfo, targetpath)
self._dbg(1, "tarfile: Unknown file type %r, " \
"extracted as reXPlar file." % tarinfo.type)

def makefifo(self, tarinfo, targetpath):
"""Make a fifo called targetpath.
"""
if hasattr(os, "mkfifo"):
os.mkfifo(targetpath)
else:
raise ExtractError("fifo not supported by system")

def makedev(self, tarinfo, targetpath):
"""Make a character or block device called targetpath.
"""
if not hasattr(os, "mknod") or not hasattr(os, "makedev"):
raise ExtractError("special devices not supported by system")

mode = tarinfo.mode
if tarinfo.isblk():
mode |= stat.S_IFBLK
else:
mode |= stat.S_IFCHR

os.mknod(targetpath, mode,
os.makedev(tarinfo.devmajor, tarinfo.devminor))

def makelink(self, tarinfo, targetpath):
"""Make a (symbolic) link called targetpath. If it cannot be created
(platform limitation), we try to make a copy of the referenced file
instead of a link.
"""
if hasattr(os, "symlink") and hasattr(os, "link"):
# For systems that support symbolic and hard links.
if tarinfo.issym():
if os.path.lexists(targetpath):
os.unlink(targetpath)
os.symlink(tarinfo.linkname, targetpath)
else:
# See extract().
if os.path.exists(tarinfo._link_target):
if os.path.lexists(targetpath):
os.unlink(targetpath)
os.link(tarinfo._link_target, targetpath)
else:
self._extract_member(self._find_link_target(tarinfo), targetpath)
else:
try:
self._extract_member(self._find_link_target(tarinfo), targetpath)
except KeyError:
raise ExtractError("unable to resolve link inside archive")

def chown(self, tarinfo, targetpath):
"""Set owner of targetpath according to tarinfo.
"""
if pwd and hasattr(os, "geteuid") and os.geteuid() == 0:
# We have to be root to do so.
try:
g = grp.getgrnam(tarinfo.gname)[2]
except KeyError:
g = tarinfo.gid
try:
u = pwd.getpwnam(tarinfo.uname)[2]
except KeyError:
u = tarinfo.uid
try:
if tarinfo.issym() and hasattr(os, "lchown"):
os.lchown(targetpath, u, g)
else:
if sys.platform != "os2emx":
os.chown(targetpath, u, g)
except EnvironmentError, e:
raise ExtractError("could not change owner")

def chmod(self, tarinfo, targetpath):
"""Set file permissions of targetpath according to tarinfo.
"""
if hasattr(os, 'chmod'):
try:
os.chmod(targetpath, tarinfo.mode)
except EnvironmentError, e:
raise ExtractError("could not change mode")

def utime(self, tarinfo, targetpath):
"""Set modification time of targetpath according to tarinfo.
"""
if not hasattr(os, 'utime'):
return
try:
os.utime(targetpath, (tarinfo.mtime, tarinfo.mtime))
except EnvironmentError, e:
raise ExtractError("could not change modification time")

#--------------------------------------------------------------------------
def next(self):
"""Return the next member of the archive as a TarInfo object, when
TarFile is opened for reading. Return None if there is no more
available.
"""
self._check("ra")
if self.firstmember is not None:
m = self.firstmember
self.firstmember = None
return m

# Read the next block.
self.fileobj.seek(self.offset)
tarinfo = None
while True:
try:
tarinfo = self.tarinfo.fromtarfile(self)
except EOFHeaderError, e:
if self.ignore_zeros:
self._dbg(2, "0x%X: %s" % (self.offset, e))
self.offset += BLOCKSIZE
continue
except InvalidHeaderError, e:
if self.ignore_zeros:
self._dbg(2, "0x%X: %s" % (self.offset, e))
self.offset += BLOCKSIZE
continue
elif self.offset == 0:
raise ReadError(str(e))
except EmptyHeaderError:
if self.offset == 0:
raise ReadError("empty file")
except TruncatedHeaderError, e:
if self.offset == 0:
raise ReadError(str(e))
except SubsequentHeaderError, e:
raise ReadError(str(e))
break

if tarinfo is not None:
self.members.append(tarinfo)
else:
self._loaded = True

return tarinfo

#--------------------------------------------------------------------------
# Little helper methods:

def _getmember(self, name, tarinfo=None, normalize=False):
"""Find an archive member by name from bottom to top.
If tarinfo is given, it is used as the starting point.
"""
# Ensure that all members have been loaded.
members = self.getmembers()

# Limit the member search list up to tarinfo.
if tarinfo is not None:
members = members[:members.index(tarinfo)]

if normalize:
name = os.path.normpath(name)

for member in reversed(members):
if normalize:
member_name = os.path.normpath(member.name)
else:
member_name = member.name

if name == member_name:
return member

def _load(self):
"""Read through the entire archive file and look for readable
members.
"""
while True:
tarinfo = self.next()
if tarinfo is None:
break
self._loaded = True

def _check(self, mode=None):
"""Check if TarFile is still open, and if the operation's mode
corresponds to TarFile's mode.
"""
if self.closed:
raise IOError("%s is closed" % self.__class__.__name__)
if mode is not None and self.mode not in mode:
raise IOError("bad operation for mode %r" % self.mode)

def _find_link_target(self, tarinfo):
"""Find the target member of a symlink or hardlink member in the
archive.
"""
if tarinfo.issym():
# Always search the entire archive.
linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname)))
limit = None
else:
# Search the archive before the link, because a hard link is
# just a reference to an already archived file.
linkname = tarinfo.linkname
limit = tarinfo

member = self._getmember(linkname, tarinfo=limit, normalize=True)
if member is None:
raise KeyError("linkname %r not found" % linkname)
return member

def __iter__(self):
"""Provide an iterator object.
"""
if self._loaded:
return iter(self.members)
else:
return TarIter(self)

def _dbg(self, level, msg):
"""Write debugging output to sys.stderr.
"""
if level <= self.debug:
print >> sys.stderr, msg

def __enter__(self):
self._check()
return self

def __exit__(self, type, value, traceback):
if type is None:
self.close()
else:
# An exception occurred. We must not call close() because
# it would try to write end-of-archive blocks and padding.
if not self._extfileobj:
self.fileobj.close()
self.closed = True
# class TarFile
f、shelve

  shelve模块是一个简单的k,v将内存数据通过文件持久化的模块,可以持久化任何pickle可支持的python数据格式

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()
g、xml处理模块

  xml是实现不同语言或程序之间进行数据交换的协议,跟json差不多,但json使用起来更简单,不过,古时候,在json还没诞生的黑暗年代,大家只能选择用xml呀,至今很多传统公司如金融行业的很多系统的接口还主要是xml。

  xml的格式如下,就是通过<>节点来区别数据结构的:

<?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>

 xml协议在各个语言里的都 是支持的,在python中可以用以下模块操作xml

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)
修改和删除xml文档内容
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')

 自己创建xml文档
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 = '33'
name2 = ET.SubElement(new_xml,"name",attrib={"enrolled":"no"})
age = ET.SubElement(name2,"age")
age.text = '19'
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
h、ConfigParser模块

  用于生成和修改常见配置文档,当前模块的名称在 python 3.x 版本中变更为 configparser。

  来看一个好多软件的常见文档格式如下
[DEFAULT]
ServerAliveInterval = 45
Compression = yes
CompressionLevel = 9
ForwardX11 = yes
[bitbucket.org]
User = hg
[topsecret.server.com]
Port = 50022
ForwardX11 = no
如果想用python生成一个这样的文档怎么做呢?

import configparser
config = configparser.ConfigParser()
config["DEFAULT"] = {'ServerAliveInterval': '45',
'Compression': 'yes',
'CompressionLevel': '9'}
config['bitbucket.org'] = {}
config['bitbucket.org']['User'] = 'hg'
config['topsecret.server.com'] = {}
topsecret = config['topsecret.server.com']
topsecret['Host Port'] = '50022' # mutates the parser
topsecret['ForwardX11'] = 'no' # same here
config['DEFAULT']['ForwardX11'] = 'yes'
with open('example.ini', 'w') as configfile:
config.write(configfile)
写完了还可以再读出来
>>> 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']
'50022'
>>> for key in config['bitbucket.org']: print(key)
...
user
compressionlevel
serveraliveinterval
compression
forwardx11
>>> config['bitbucket.org']['ForwardX11']
'yes'

 I、hashlib模块  

  用于加密相关的操作,3.x里代替了md5模块和sha模块,主要提供 SHA1, SHA224, SHA256, SHA384, SHA512 ,MD5 算法
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())
 python 还有一个 hmac 模块,它内部对我们创建 key 和 内容 再进行处理然后再加密

1 import hmac
2 h = hmac.new('wueiqi')
3 h.update('hellowo')
4 print h.hexdigest()

j、re模块
'.' 默认匹配除\n之外的任意一个字符,若指定flag DOTALL,则匹配任意字符,包括换行
'^' 匹配字符开头,若指定flags MULTILINE,这种也可以匹配上(r"^a","\nabc\neee",flags=re.MULTILINE)
'$' 匹配字符结尾,或e.search("foo$","bfoo\nsdfsf",flags=re.MULTILINE).group()也可以
'*' 匹配*号前的字符0次或多次,re.findall("ab*","cabb3abcbbac") 结果为['abb', 'ab', 'a']
'+' 匹配前一个字符1次或多次,re.findall("ab+","ab+cd+abb+bba") 结果['ab', 'abb']
'?' 匹配前一个字符1次或0次
'{m}' 匹配前一个字符m次
'{n,m}' 匹配前一个字符n到m次,re.findall("ab{1,3}","abb abc abbcbbb") 结果'abb', 'ab', 'abb']
'|' 匹配|左或|右的字符,re.search("abc|ABC","ABCBabcCD").group() 结果'ABC'
'(...)' 分组匹配,re.search("(abc){2}a(123|456)c", "abcabca456c").group() 结果 abcabca456c


'\A' 只从字符开头匹配,re.search("\Aabc","alexabc") 是匹配不到的
'\Z' 匹配字符结尾,同$
'\d' 匹配数字0-9
'\D' 匹配非数字
'\w' 匹配[A-Za-z0-9]
'\W' 匹配非[A-Za-z0-9]
's' 匹配空白字符、\t、\n、\r , re.search("\s+","ab\tc1\n3").group() 结果 '\t'

'(?P<name>...)' 分组匹配 re.search("(?P<province>[0-9]{4})(?P<city>[0-9]{2})(?P<birthday>[0-9]{4})","371481199306143242").groupdict("city") 结果{'province': '3714', 'city': '81', 'birthday': '1993'}

最常用的匹配语法

1 re.match 从头开始匹配
2 re.search 匹配包含
3 re.findall 把所有匹配到的字符放到以列表中的元素返回
4 re.splitall 以匹配到的字符当做列表分隔符
5 re.sub 匹配字符并替换
反斜杠的困扰
  与大多数编程语言相同,正则表达式里使用"\"作为转义字符,这就可能造成反斜杠困扰。假如你需要匹配文本中的字符"\",那么使用 编程语言表示的正则表达式里将需要4个反斜杠"\\\\":前两个和后两个分别用于在编程语言里转义成反斜杠,转换成两个反斜杠后再在正则表达式里转义成 一个反斜杠。Python里的原生字符串很好地解决了这个问题,这个例子中的正则表达式可以使用r"\\"表示。同样,匹配一个数字的"\\d"可以写成 r"\d"。有了原生字符串,你再也不用担心是不是漏写了反斜杠,写出来的表达式也更直观。

  仅需轻轻知道的几个匹配模式

1 re.I(re.IGNORECASE): 忽略大小写(括号内是完整写法,下同)
2 M(MULTILINE): 多行模式,改变'^'和'$'的行为(参见上图)
3 S(DOTALL): 点任意匹配模式,改变'.'的行为

 

posted @ 2016-08-25 22:39  小伙真精神  阅读(286)  评论(0编辑  收藏