PS3:1

from string import *

def countSubStringMatch(target,key):
    """Enter target string and search key string"""
    assert isinstance(target,str), "Target value not string"
    assert isinstance(key,str), "Key value not string"

    length=0
    index=0
    count=0
    for i in range(0,len(target)):
        index=target.find(key,index+length)
        length=len(key)
        if index!=-1:
            count+=1
        elif index==-1 and count==0:
            return -1
        else:
            return count