Question

Hi
I have two CSV files as input, for example:

file1 :

AK163828 chr5 s1 + e1 cttt 4
AK163828 chr5 s2 + e2 gtca 4
AK168688 chr6 s3 + e3 ggcg 4
AK168688 chr6 s4 + e4 tctg 4

file2 :

chr6s3+e3 ggcg
chr5s1+e1 cttt
chr6s4+e4 tata
chr5s2+e2 ggcg

#as you can see the file2 is randomly sorted

I want to compare column 1 of file2 with column 2, 3, 4, 5 merged of file1 and at the same time the column 2 of file2 with column 6 of file 1, and select only the matching lines.

The desired output is

chr6s3+e3 ggcg
chr5s1+e1 cttt

I tried to use this code:

import csv

reader1 = csv.reader(open(file1), dialect='excel-tab' )
reader2 = csv.reader(open(file2), dialect='excel-tab' )

     for row1, row2 in zip(reader1,reader2):
            F1 = row1[1] + row1[2] + row1[3] + row1[4] + '\t' row1[5]
            F2 = row2[0] + '\t' + row2[1]
            print set(F1) & set(F2)

But it doesn’t work. Can you help me to fix my code or give me an other way to do it?
Thanks for your help!

Answer 1

Quick and dirty:

import csv

file1 = 'C:/Users/Me/Desktop/file1'
file2 = 'C:/Users/Me/Desktop/file2'

reader1 = csv.reader(open(file1))
reader2 = csv.reader(open(file2))

F1 = set(''.join(row1[0].strip().split()[1:6]) for row1 in reader1)
F2 = set(''.join(row2[0].strip().split()) for row2 in reader2)

for sequence in F1.intersection(F2):
    print(sequence[:-4]),
    print('\t'),
    print(sequence[-4:])

Output:

chr6s3+e3   ggcg
chr5s1+e1   cttt