input="""img.png	description
bbb	222
ccc	333
ddd	444
eee	555
fff	666"""

#define number of columns
cols=3

def process(input):
    
     #split into lines   
    output=input.split('\n')

     #map 
    for i in range(0, len(output),cols):
        print "<row>"
        
         #split lines into columns
        for col in range(0,cols):
            
            print "	<entry><para><mediaobject><imageobject><imagedata fileref=\"images/%s\" align=\"center\" width=\"100%\" /></imageobject></mediaobject></para></entry>"  % str(output[i+col].split('\t')[0])
        print "</row>"

        print "<row>"
        
        for col in range(0,cols):
            print "	<entry><para>", str(output[i+col].split('\t')[1]), "</para></entry>"
        
        print "</row>"
        
        
process(input)