def subStringMatchExact(target,key):
    bookmark=0
    location=()
    #While the find function does not fail to find a value
    while bookmark!=-1:
        #Store the index of the first match in bookbark.
        bookmark=find(target,key,bookmark)
        #Add bookmark to a tuple
        location=location+(bookmark,)
        #Find the next value of bookmark here so that if it is -1 we can stop before looping again.
        bookmark=find(target,key,bookmark+1)
    return location

def constrainedMatchPair(firstMatch,secondMatch,length):
    listmatch=()
    for n in range(0,len(firstMatch)):
        for k in range(0,len(secondMatch)):
            if firstMatch[n]+length+1==secondMatch[k]:
                listmatch=listmatch+(firstMatch[n],)
    return listmatch