Python binary string and list

1. #split data to list
2. def data2list(datapath):
3.     f = open(datapath,'r+b')
4.     print 'f',f
5.    
6.     datalist = []
7.     data = f.read()
8.    
9.     limit = len(data)
10.    
11.     print 'Origin Data Size = %d  byte' %limit
12.     for i in range(limit/256+1):
13.         datalist.append(data[i*256:i*256+256])
14.  
15.     f.close()
16.     return datalist
17.  
18. #converge list element to binary data
19. def list2data(list):   
20.     binary = ''
21.     j = len(list)
22.     for i in range(j):
23.         binary = binary + list[i]
24.  
25.     return binary