#!/usr/bin/env python
#-*- coding:utf-8 -*-
 
'''
計算文檔的TF-IDF
'''
import codecs
import os
import math
import shutil
 
#讀取文本文件
def readtxt(path):
 with codecs.open(path,"r",encoding="utf-8") as f:
  content = f.read().strip()
 return content
 
#統計詞頻
def count_word(content):
 word_dic ={}
 words_list = content.split("/")
 del_word = ["\r\n","/s"," ","/n"]
 for word in words_list:
  if word not in del_word:
   if word in word_dic:
    word_dic[word] = word_dic[word]+1
   else:
    word_dic[word] = 1
 return word_dic
 
#遍歷文件夾
def funfolder(path):
 filesArray = []
 for root,dirs,files in os.walk(path):
  for file in files:
   each_file = str(root+"http://"+file)
   filesArray.append(each_file)
 return filesArray
 
 
#計算TF-IDF
def count_tfidf(word_dic,words_dic,files_Array):
 word_idf={}
 word_tfidf = {}
 num_files = len(files_Array)
 for word in word_dic:
  for words in words_dic:
   if word in words:
    if word in word_idf:
     word_idf[word] = word_idf[word] + 1
    else:
     word_idf[word] = 1
 for key,value in word_dic.items():
  if key !=" ":
   word_tfidf[key] = value * math.log(num_files/(word_idf[key]+1))
 
 #降序排序
 values_list = sorted(word_tfidf.items(),key = lambda item:item[1],reverse=True)
 return values_list
 
#新建文件夾
def buildfolder(path):
 if os.path.exists(path):
  shutil.rmtree(path)
 os.makedirs(path)
 print("成功創建文件夾！")
 
#寫入文件
def out_file(path,content_list):
 with codecs.open(path,"a",encoding="utf-8") as f:
  for content in content_list:
   f.write(str(content[0]) + ":" + str(content[1])+"\r\n")
 print("well done!")
 
def main():
 #遍歷文件夾
 folder_path = r"分詞結果"
 files_array = funfolder(folder_path)
 #生成語料庫
 files_dic = []
 for file_path in files_array:
  file = readtxt(file_path)
  word_dic = count_word(file)
  files_dic.append(word_dic)
 #新建文件夾
 new_folder = r"tfidf計算結果"
 buildfolder(new_folder)
 
 #計算tf-idf,并將結果存入txt
 i=0
 for file in files_dic:
  tf_idf = count_tfidf(file,files_dic,files_array)
  files_path = files_array[i].split("http://")
  #print(files_path)
  outfile_name = files_path[1]
  #print(outfile_name)
  out_path = r"%s//%s_tfidf.txt"%(new_folder,outfile_name)
  out_file(out_path,tf_idf)
  i=i+1
 
if __name__ == '__main__':
 main()