Python script to find a words

Question

There is a python script that loads cvs file with some part of text in every cell in the column A. I want to modify the script to get information how many times the phrase 'green book' appears in every cell.

When I run this code it count only one mention this phrase in cell but there some of the cell contain at least 2 mentions
What do I do wrong?

df_['CheckWords'] = df_['transcript'].map(check_words)

def check_words(text):
i = 0
if len(i in text for i == 'green book'):
i += 1
return (i)

Answer 1

May be i understand it wrong, so please correct me. I feel that some more information is needed from your side.
I assume, that you want to find the number of occurrences of a substring in a string.

s = 'each time i saw a green book, it looks like "GREEN Book"'
sub = 'green book'
count = s.lower().count(sub.lower())
print(count) # result is 2

Answer 2

Your code can never increase i higher than 1. But I would like to add, that you could compare the length directly, if you first replace all occurrences and divide the difference by the length of the search string.