Python的杂七杂八

1. 读取文件列表

import os
print os.listdir('.')

files = [f for f in os.listdir('.') if re.match("*.jpg", f) ]

 

2. 读取文件自动关闭

with open(filename) as file:
    for line in file:
         print line

 

3.两个字典相加

  有如下两个字典

a = dict()
a['cat'] = 1
a['fish'] = 10
a['aardvark'] = 1000

b = dict()
b['cat'] = 2
b['dog'] = 200
b['aardvark'] = 2000

 目标相加之后获得如下字典：

{'cat': 3, 'fish': 10, 'dog': 200, 'aardvark': 3000}

 可以通过如下方法获得：

dict( (n, a.get(n, 0)+b.get(n, 0)) for n in set(a)|set(b) )

 

4.将文本文件转换为二进制文件

import binascii
with open ( "regular_english_file.txt", "r" ) as myfile:
    print bin( int( binascii.hexlify( myfile.read() ), 16 ) );