Ch 8 Practice: Sentiment Analysis and Loop Variables

23.5. Ch 8 Practice: Sentiment Analysis and Loop Variables#

Now it’s your turn to practice sentiment analysis and loop variables

23.5.1. Sentiment Analyasis#

First run the code to load up the Sentiment Intensity Analyzer

import nltk
nltk.download(["vader_lexicon"])
from nltk.sentiment import SentimentIntensityAnalyzer
sia = SentimentIntensityAnalyzer()

[nltk_data] Downloading package vader_lexicon to
[nltk_data]     C:\Users\kmthayer\AppData\Roaming\nltk_data...
[nltk_data]   Package vader_lexicon is already up-to-date!

Also, look at this example from the demo of running sentiment analysis:

sentence = "I love love love pizza!!!!!!!!"
sia.polarity_scores(sentence)["compound"]

0.941

Now, copy that two lines of code above, and try out your own sentences, and run the sentiment analysis on them

sentence = "This is an ok example"
sia.polarity_scores(sentence)["compound"]

0.296

Try several sentences and see how the Sentiment Intensity Analyzer handles them

sentence = "This is a horrible example"
sia.polarity_scores(sentence)["compound"]

-0.5423

23.5.2. Loop variables#

Now let’s practice with loop variables.

Below is a for loop which goes through each letter in the word “Mississipi”.

for letter in "Mississipi":
    print(letter)

M
i
s
s
i
s
s
i
p
i

Make another copy of that loop, but add a variable before the loop called num_letters and use it count how many letters were in the word “Mississipi”. At the end display the number of letters.

num_letters = 0

for letter in "Mississipi":
    print(letter)
    num_letters += 1
    
print("There were " + str(num_letters) + " letters")

M
i
s
s
i
s
s
i
p
i
There were 10 letters

Make another copy of what you just did, but this time also count the number of “i”s. Make a variable called num_i to count how many “i”s.

Hint: To see if a letter is an “i”, check if letter == "i"

At the end print out how many of the letters were “i”s and what percentage of the word was “i”s.

num_letters = 0
num_i = 0

for letter in "Mississipi":
    print(letter)
    num_letters += 1
    
    if(letter == "i"):
        num_i += 1
    
print("There were " + str(num_letters) + " letters")

percent_i = num_i / num_letters * 100

print("i's made up " + str(percent_i) + " percent of the word")

M
i
s
s
i
s
s
i
p
i
There were 10 letters
i's made up 40.0 percent of the word
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