Count number of occurrences of a given substring in a string

Question

How can I count the number of times a given substring is present within a string in Python?

For example:

>>> \'foo bar foo\'.numberOfOccurre         


        

Answer 1

import re
d = [m.start() for m in re.finditer(seaching, string)] 
print (d)

This finds the number of times sub string found in the string and displays index.

Answer 2

string="abc"
mainstr="ncnabckjdjkabcxcxccccxcxcabc"
count=0
for i in range(0,len(mainstr)):
    k=0
    while(k<len(string)):
        if(string[k]==mainstr[i+k]):
            k+=1
        else:
            break   
    if(k==len(string)):
        count+=1;   
print(count)

Answer 3

You can count the frequency using two ways:

1. Using the count() in str:

   a.count(b)

2. Or, you can use:

   len(a.split(b))-1

Where a is the string and b is the substring whose frequency is to be calculated.

Answer 4

I'm not sure if this is something looked at already, but I thought of this as a solution for a word that is 'disposable':

for i in xrange(len(word)):
if word[:len(term)] == term:
    count += 1
word = word[1:]

print count

Where word is the word you are searching in and term is the term you are looking for

Answer 5

The best way to find overlapping sub-string in a given string is to use the python regular expression it will find all the overlapping matching using the regular expression library. Here is how to do it left is the substring and in right you will provide the string to match

print len(re.findall('(?=aa)','caaaab'))
3

Answer 6

You could use the startswith method:

def count_substring(string, sub_string):
    x = 0
    for i in range(len(string)):
        if string[i:].startswith(sub_string):
            x += 1
    return x