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#                                #
# Last modified 2017/03/22       # 
#                                #
# Georgi Marinov                 #
#                                # 
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import sys
import string

def run():

    if len(sys.argv) < 5:
        print 'usage: python %s file1 fielID1 file2 fielID2 outfilename' % sys.argv[0]
        sys.exit(1)

    file1 = sys.argv[1]
    file2 = sys.argv[3]
    fieldID1 = int(sys.argv[2])
    fieldID2 = int(sys.argv[4])
    outfilename = sys.argv[5]

    ItemList1 = []
    linelist = open(file1)
    for line in linelist:
        if line.startswith('#') or line.strip() == '':
            continue
        fields = line.strip().split('\t')
        ItemList1.append(fields[fieldID1])

    ItemList2 = []
    linelist = open(file2)
    for line in linelist:
        if line.startswith('#') or line.strip() == '':
            continue
        fields = line.strip().split('\t')
        ItemList2.append(fields[fieldID2])

    outfile = open(outfilename,'w')

    for item1 in ItemList1:
        for item2 in ItemList2:
            outline = item1 + '\t' + item2
            outfile.write(outline + '\n')

    outfile.close()

run()