python - Conditionally remove lines between two patterns in a file -

input file :

<chunk of text> pattern1 abc efg hij pattern2 klm nop pattern3 <chunk of text> 

output file :

<chunk of text>  <chunk of text> 

how remove lines between pattern 1 , pattern 3 of file(inclusive) if there pattern2 between them

import sys,re flag,delete,store = false,false,"" line in open(sys.argv[1]):     if re.search('pattern1',line):          flag = true         print store         store = line         continue     if flag :         store += line         if re.search('pattern2',line): delete = true         if re.search('pattern3',line) :             if not delete : print store             store = ''             flag = false             delete = false     else : print line, print store