Write a recursive code to print the number of occurrences of substring "hi" that is not preceded by substring "x" created by hygull - https://repl.it/FEx4/0

Write a recursive code to print the number of occurrences of substring "hi" that is not preceded by substring "x".go

"""
    coded_on : 10 January 2017.
    aim      : Write a recursive code to print the number of occurrences of substring "hi" that is not preceded by substring "x"
    coded_by : Rishikesh Agrawani.
"""
def abcd(s):
    try: 
        index=s.index("hi")
        if index==0:
            return 1+abcd(s[index+1:])
        else:
            if s[index-1]!="x":
                return 1+abcd(s[index+1:])
            else:
                return abcd(s[index+1:])
    except:
        return 0


#Testing with different cases  

print abcd("hixhifhjhi")                #2
print abcd("xhixhi")                    #0
print abcd("hixhix")                    #1
print abcd("hxhixh")                    #0
print abcd("hiabcdhiandxhiandchi")      #3
print abcd("dfgxhigopher")              #0
print abcd("optxhixhixhixhiandhihello") #1