#!/usr/bin/python from subprocess import check_call import subprocess import gzip ''' $ zcat 160121_I133_FCH5LL5BBXX_L8_RSZADPI007179-107_2.fq.gz |head -4 >o3 $ cat o3 @K00133:143:H5LL5BBXX:8:1101:1194:1103 2:N:0:NCGCCGTG NAAGGAGAAGTTCCCATAGCAACAGCACCATTTTTTCCAGGGAAAAGGAGGAAAGAATCAAGGATGCGAAAGAGGGAATCAAAGCAGCTTAAGGGATATAAAAAAAACAGGGATTGTTCATGAATTATGGACAAGGCAGCTGAGAATTCC + #AAFFJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJA-<7-77A<7AJJF<AJJJJJF7JFAJF7AJJFJJJJJJJFF-AFJFJJJJJ--FFJJJJJJAAJFF<AJJJJJF777-----<-7F7-<--<<<<<7F<--7)--A7FF--<7 ''' p1=subprocess.Popen('cat o3',shell=True,stdout=subprocess.PIPE) p2=subprocess.Popen('head -4',shell=True,stdin=p1.stdout,stdout=subprocess.PIPE) print 'oneline:',p2.stdout.readline() print 'oneline:',p2.stdout.readline() print 'onefile:',p2.stdout.read() ''' oneline: @K00133:143:H5LL5BBXX:8:1101:1194:1103 2:N:0:NCGCCGTG oneline: NAAGGAGAAGTTCCCATAGCAACAGCACCATTTTTTCCAGGGAAAAGGAGGAAAGAATCAAGGATGCGAAAGAGGGAATCAAAGCAGCTTAAGGGATATAAAAAAAACAGGGATTGTTCATGAATTATGGACAAGGCAGCTGAGAATTCC onefile: + #AAFFJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJA-<7-77A<7AJJF<AJJJJJF7JFAJF7AJJFJJJJJJJFF-AFJFJJJJJ--FFJJJJJJAAJFF<AJJJJJF777-----<-7F7-<--<<<<<7F<--7)--A7FF--<7 ''' ''' $ zcat 1.txt.gz 111111111111111 yyyyyyyyyyyyyyyyyyyyyyy jjjjjjjjjjjjjjjjjj nnnnnnnnnnnn 111111111111111111 ''' check_call('zcat 1.txt.gz |head -4',shell=True) ''' 111111111111111 yyyyyyyyyyyyyyyyyyyyyyy jjjjjjjjjjjjjjjjjj nnnnnnnnnnnn ''' f= gzip.open('1.txt.gz','rb') line = f.readline() print line ''' 111111111111111 '''