Đầu tiên cần cài thư viện ví dụ trên linux ubuntu
- Open terminal(Linux).
- sudo pip3 install nltk
- python3
- import nltk
- nltk.download(‘all’)
Trên windows thì
python -m pip install nltk
hoặc pip install nltk
# Program to measure similarity between
# two sentences using cosine similarity.
from nltk.corpus import stopwords
from nltk.tokenize import word_tokenize
# X = input("Enter first string: ").lower()
# Y = input("Enter second string: ").lower()
X ="I love horror movies"
Y ="Lights out is a horror movie"
# tokenization
X_list = word_tokenize(X)
Y_list = word_tokenize(Y)
# sw contains the list of stopwords
sw = stopwords.words('english')
l1 =[];l2 =[]
# remove stop words from string
X_set = {w for w in X_list if not w in sw}
Y_set = {w for w in Y_list if not w in sw}
# form a set containing keywords of both strings
rvector = X_set.union(Y_set)
for w in rvector:
if w in X_set: l1.append(1) # create a vector
else: l1.append(0)
if w in Y_set: l2.append(1)
else: l2.append(0)
c = 0
# cosine formula
for i in range(len(rvector)):
c+= l1[i]*l2[i]
cosine = c / float((sum(l1)*sum(l2))**0.5)
print("similarity: ", cosine)
Kết quả chúng ta thu được
similarity: 0.6666666666666666
