Python을 사용하여 텍스트를 병합하는 방법

cat employee.txt:
100 Jason Smith
200 John Doe
300 Sanjay Gupta
400 Ashok Sharma

cat bonus.txt:
100 $5,000
200 $500
300 $3,000
400 $1,250

400 ashok sharma $1,250
100 jason smith  $5,000
200 john doe  $500
300 sanjay gupta  $3,000

#! /usr/bin/env python
#coding=utf-8
fp01=open("bonus.txt","r")
a=[]
for line01 in fp01:
    a.append(line01)
fp02=open("employee.txt","r")
fc02=sorted(fp02,key=lambda x:x.split()[1])
for line02 in fc02:
    i=0
    while line02.split()[0]!=a[i].split()[0]:
        i+=1
    print "%s %s %s %s" % (line02.split()[0],line02.split()[1],line02.split()[2],a[i].split()[1])
fp01.close()
fp02.close()