Bob Counter in Python

Question

Using Python 2.7, I was attempting to count the number of occurances of \'bob\' in the phrase \'bobbbobobboobobookobobbobbboj.\' To do this, I wrote the code below:

Answer 1

start=0
count=0 
while start<=len(s):
    n=s.find('b',start,len(s))
    prnt=(s[start:start+3])
    if prnt =='bob':
       start=n+2 
       count+=1
    else:
        start+=1        
print count