6.9-2

# 총 문서(검색어)의 수
N = len(docs) 

def tf(t, d):
  return d.count(t)

def idf(t):
  df = 0
  for doc in docs:
    df += t in doc
  return log(N/(df+1))

def tfidf(t, d):
  return tf(t,d)* idf(t)
  
  result = []

# 아래 연산을 반복
for i in range(N):
  result.append([])
  d = docs[i]
  for j in range(len(vocab)):
    t = vocab[j]
    result[-1].append(tf(t, d))

tf_ = pd.DataFrame(result, columns = vocab)

result = []
for j in range(len(vocab)):
    t = vocab[j]
    result.append(idf(t))

idf_ = pd.DataFrame(result, index=vocab, columns=["IDF"])
idf_

result = []
for i in range(N):
  result.append([])
  d = docs[i]
  for j in range(len(vocab)):
    t = vocab[j]
    result[-1].append(tfidf(t,d))

tfidf_ = pd.DataFrame(result, columns = vocab)
tfidf_