Python efficient way to check if very large string contains a substring

Question

Python is not my best language, and so I\'m not all that good at finding the most efficient solutions to some of my problems. I have a very large string (coming from a 30 MB

Answer 1

small_string = "This is a line"
big_string = "This is a line This is another line\nThis is yet another"

test= big_string.split("This is a line" ,1)

if len(test)==2:

    print "it`s there"

elif len(test)!=2:

    print "it`s not"