from string import*
def subStringMatchExact(target,key,z=[],x=0):
''' Where z begins as an empty set, to become the output tuple and x starts at 0 to hold the beginning search'''
index = find(target,key,x)
if index == -1:
return tuple(z)
if index != -1:
z.append(index)
x = index + 1
subStringMatchExact(target,key,z,x)
print subStringMatchExact("SUCCESS","S")