# Importing the nltk libraries
import nltk
from nltk.stem import PorterStemmer
from nltk.corpus import stopwords
paragraph = 'Scorpions are predatory arachnids of the order Scorpiones. They have eight legs, a pair of grasping pincers and a narrow, segmented tail, often carried in a characteristic forward curve over the back and always ending with a stinger. There are over 2,500 described species. They mainly live in deserts but have adapted to a wide range of environments. Most species give birth to live young, and the female cares for the juveniles while their exoskeletons harden, transporting them on her back. Scorpions primarily prey on insects and other invertebrates, but some species take vertebrates. They use their pincers to restrain and kill prey. Scorpions themselves are preyed on by larger animals. Their venomous sting can be used both for killing prey and for defense. Only about 25 species have venom capable of killing a human. In regions with highly venomous species, human fatalities regularly occur.'
sentence = nltk.sent_tokenize(paragraph)
stemmer = PorterStemmer()
# Stemming
for i in range(len(sentence)):
words = nltk.word_tokenize(sentence[i])
words = [stemmer.stem(word) for word in words if word not in set(stopwords.words('english'))]
sentence[i] = ' '.join(words)
print(sentence)
# Basically what happens when we use the stopwords is that for example when we wake a sentence like "Hello my name is Avinash Kumar"
# When we apply the stop words on this, all the words like 'my', 'is' and 'this' all these which don't have any meaning on their own would be removed.
# So all these words will be removed and then stemming is applied.
# What is stemming?
# Basically stemming means for example we have a word like
# History
# Historied
# Histories
# Upon stemming on these 3 words it will be converted to histori and replaced ( But what is histori ? it's not a word from the dictionary and has no meaning)
# This issue will be solved in the other topic called lemmatization which will be discussed in the next code.
