Category: 编程学习

There are a few useful tips to convert a Python list (or any other iterable such as a tuple) to a string for display.

First, if it is a list of strings, you may simply use join this way:

>>> mylist = ['spam', 'ham', 'eggs']
>>> print ', '.join(mylist)
spam, ham, eggs

Using the same method, you might also do this:

>>> print '\n'.join(mylist)
spam
ham
eggs

However, this simple method does not work if the list contains non-string objects, such as integers.

If you just want to obtain a comma-separated string, you may use this shortcut:

>>> list_of_ints = [80, 443, 8080, 8081]
>>> print str(list_of_ints).strip('[]')
80, 443, 8080, 8081

Or this one, if your objects contain square brackets:

>>> print str(list_of_ints)[1:-1]
80, 443, 8080, 8081

Finally, you may use map() to convert each item in the list to a string, and then join them:

>>> print ', '.join(map(str, list_of_ints))
80, 443, 8080, 8081
>>> print '\n'.join(map(str, list_of_ints))
80
443
8080
8081

自己写的一个Python遍历文件脚本，对查到的文件进行特定的处理。没啥技术含量，但是也记录一下吧。

#!/usr/bin/python
# -*- coding: utf-8 -*-
import sys
import os
import shutil
dir = "/mnt/Packages"
class Packages:
    def __init__(self,srcdir,desdir):
        self.sdir=srcdir
        self.ddir=desdir
    def check(self):
        print('program start...')
        for dirpath, dirnames, filenames in os.walk(self.sdir):   #遍历文件
            for filename in filenames:
                thefile=os.path.join(dirpath,filename)            #文件的绝对地址
                try:
                    if os.path.splitext(thefile)[1]=='.rpm':      #筛选.rpm格式的文件
                        #print('Fount rpm package: ' + thefile)
                        if 'inspuer' in os.popen('rpm -qpi ' + thefile).read().rstrip():
                            print('Found error package: ' + thefile)
                            shutil.copy(thefile, self.ddir)  #将错误文件复制到desdir目录
                            f = open('list.txt', 'a')    #将错误文件列表写入到list.txt
                            f.write(filename + '\n')
                            f.close()
                except IOError, err:
                    print err
                    sys.exit()

if __name__ == '__main__':
    dir=Packages('/mnt/cdrom','/mnt/erpm')   #源目录为/mnt/cdrom，目标目录为/mnt/erpm
    dir.check()

Python re正则匹配中文，其实非常简单，把中文的unicode字符串转换成utf-8格式就可以了，然后可以在re中随意调用将输入的utf-8中文解密为unicode，然后交由python处理（2014.10.09感谢QQ85897930纠正）。

unicode中中文的编码为/u4e00-/u9fa5，因此正则表达式u”[\u4e00-\u9fa5]+”可以表示一个或者多个中文字符

>>> import re

>>> s='中文：123456aa哈哈哈bbcc'.decode('utf8')
>>> s
u'\u4e2d\u6587\uff1a123456aa\u54c8\u54c8\u54c8bbcc'
>>> print s
中文：123456aa哈哈哈bbcc

>>> re.match(u"[\u4e00-\u9fa5]+",s)
<_sre.SRE_Match object at 0xb77742c0>

>>> pat='中文'.decode("utf8")
>>> re.search(pat,s)
<_sre.SRE_Match object at 0x16a16df0>

>>> newpat='这里是中文内容'.decode("utf8")

>>> news=re.sub(pat,newpat,s)
>>> print news
这里是中文内容：123456aa哈哈哈bbcc

文件的复制
file类中没有提供专门的文件复制函数，因此只能通过使用文件的读写函数来实现文件的复制。这里仅仅给出范例：

src = file("myfile.txt", "w+")
temp = ["hello world! \n"]
src.writelines(temp)
src.close()

src = file("myfile.txt", "r+")
des = file("myfile2.txt", "w+")
des.writelines(src.read())
src.close()
des.close()