count_word_in_text.py

# First we def (define) a function that takes 2 arguments:
# 	1. argument is the text to look for occurances
# 	2. argument is the word_to_count
def count_word_in_text(text, word_to_count):
	# The count of our word that we're counting 
    count = 0

    # The text index looking from
    start = 0

    # Setting all the text to lowercase to match different casing
    lowercase_text = text.lower()

    # Setting the word to count to lowercase to match all the occurences in the loop
    lowercase_word_to_count = word_to_count.lower()

    while True:
    	# Here we find the index of the word in our text
    	# Ex
    	# text = 'Hello world'
    	# word_to_count = 'Hello'
    	# then index of word start is 0 because the word Hello starts on index 0 in the text
    	# if the word_to_count = 'world' - the index of word start is 6 because the word world
    	# starts on the 6. location in the text
        start = lowercase_text.find(lowercase_word_to_count, start) + 1

        # if start (index of the word) is above 0 then increment the count of words by 1
        if start > 0:
        	# here we increment the count
            count += 1

        # Else which meanes the word dosn't exist
        else:
        	# We just return the final count
            return count

# Here we save the test text into a variable test_text
test_text = '''
To Sherlock Holmes she is always the woman. I have seldom heard him
mention her under any other name. In his eyes she eclipses and
predominates the whole of her sex. It was not that he felt any
emotion akin to love for Irene Adler. All emotions, and that one
particularly, were abhorrent to his cold, precise but admirably
balanced mind. He was, I take it, the most perfect reasoning and
observing machine that the world has seen, but as a lover he would
have placed himself in a false position. He never spoke of the softer
passions, save with a gibe and a sneer. They were admirable things
for the observer--excellent for drawing the veil from men's motives
and actions. But for the trained reasoner to admit such intrusions
into his own delicate and finely adjusted temperament was to
introduce a distracting factor which might throw a doubt upon all his
mental results. Grit in a sensitive instrument, or a crack in one of
his own high-power lenses, would not be more disturbing than a strong
emotion in a nature such as his. And yet there was but one woman to
him, and that woman was the late Irene Adler, of dubious and
questionable memory.
'''

# Here we count the word "woman"
count_one = count_word_in_text(test_text, "woman")
print(count_one)

# Here we count the word "and"
count_two = count_word_in_text(test_text, "and")
print(count_two)