Shell Programming and Scripting

#!/usr/bin/env python
file1={} # store file1 contents in a dictionary
for line in open("file1"):
    line=line.strip().split("|")     # split the line on "|"
    file1['|'.join(line[:3])] = line[-1] #  store the first 3 elements as the key and last element as the value

for line in open("file2"): #now iterate file 2
    line=line.strip().split("|")  # you should know what his does
    one='|'.join(line[:3]) # get the first 3 elements together
    if file1.has_key(one):    #check against file1 dictionary using the key
        print "%s|%s|%s" %(one,line[-1],file1[one]) #do the printing
    else:
        print "%s|%s|%s" %(one,line[-1],"0")