Script to extract value corresponding to one column in file 1 from two other files.

value_extractor.py

# Input files from which first 5 columns have to be retained: input0.csv
# Input files from which column's content have to be copied: input1,input2, input3.csv
# It searches value in other three columns from csv files, corresponding to column value in input0.csv 
# Author Ravi Prakash Giri

import os

file0=open('input0.csv','r')
file1=open('input1.csv','r')
file2=open('input2.csv','r')
file3=open('input3.csv','r')
file4=open('output742.csv','w')

print file0.readline()
print file1.readline()
print file2.readline()
print file3.readline()

input0=[]
input1=[]
input2=[]
input3=[]


for line in file0:
 	input0.append([i for i in line.split(',') if i])

for line in file1:
 	input1.append([i for i in line.split(',') if i])

for line in file2:
 	input2.append([i for i in line.split(',') if i]) 	 	


for line in file3:
 	input3.append([i for i in line.split(',') if i])

reslut=[]
for keyline in input0:
	key=keyline[1]
	r1='-'
	r2='-'
	r3='-'
	tmp=[i.strip('\r\n') for i in keyline[1:6]]
	ln=len(tmp)
	#print ln,ln
	if (5-ln):
		i=0
		while i<(5-ln):
			#print 'in'
			i=i+1
			tmp.append('-')
		#print "->",len(tmp)
	for line in input1:
		if key==line[2]:
			r1=line[-1].strip('\r\n')
	for line in input2:
		if key==line[2]:
			r2=line[-1].strip('\r\n')
	for line in input3:
		if key==line[2]:
			r3=line[-1].strip('\r\n')
	reslut.append(tmp+[r1,r2,r3])

for line in reslut:
	file4.write(str(line).strip('[]')+'\n')

file4.close()