'''
Created on Mar 1, 2018

'''
from numpy import *

def textParse(bigString):    #input is big string, #output is word list
	"""	
		接受一个大字符串并将其解析为字符串列表。该函数去掉少于两个字符的字符串，并将所有字符串转换为小写。
	"""
    import re
    listOfTokens = re.split(r'\W*', bigString)
    return [tok.lower() for tok in listOfTokens if len(tok) > 2] 
    
def createVocabList(dataSet):
	"""
		创建一个包含在所有文档中出现的不重复的词的列表。
	"""
    vocabSet = set([])  #create empty set
    for document in dataSet:
        vocabSet = vocabSet | set(document) #union of the two sets
    return list(vocabSet)

def bagOfWords2VecMN(vocabList, inputSet):
	"""
		获得文档向量，向量中的数值代表词汇表中的某个单词在一篇文档中的出现次数
	"""
    returnVec = [0]*len(vocabList)
    for word in inputSet:
        if word in vocabList:
            returnVec[vocabList.index(word)] += 1
    return returnVec