Looking for a pattern in a list
I guess that the first part of your code is just to initialize the sample data.

Then here are a few things:


Separate initialization and main loop. I know this is just an exercise, but always doing it will help you keep the mindset.
If you only need to count something, just count it. Don't keep track of everything.
If you only need to check the existence of something, use a boolean value and return as soon as you've found it. Adding elements to a list so that at the end you can count them and return a boolean based on the count is definitely not an efficient way to do it.
What you call cursor is actually an integer, not an object, so the name index may be more appropriate
If you want to give the chance to start searching from a specific index, you may also want to have a default value for that parameter (0 looks like a good choice)
You don't need the third parameter, that's what you are going to return


This is my attempt at it:

big_s = []

def init_big_s():
    for i in range(1,101):
        if i % 10 == 0:
            big_s.extend([1,2,3])
        else:
            big_s.append(i)

def looking_patt(pattern, index=0):
    for i in big_s:
        if i == pattern[index]:
            index += 1
            if index == len(pattern):
                return True
        else:
            index = 0  
    return False

init_big_s()
print looking_patt([1, 2, 3])