class_docstr: ISRI Arabic stemmer based on algorithm: Arabic Stemming without a root dictionary.
  Information Science Research Institute. University of Nevada, Las Vegas, USA.
  
  A few minor modifications have been made to ISRI basic algorithm.
  See the source code of this module for more information.
  
  isri.stem(token) returns Arabic root for the given token.
  
  The ISRI Stemmer requires that all tokens have Unicode string types.
  If you use Python IDLE on Arabic Windows you have to decode text first
  using Arabic '1256' coding.
class_docstr_tok: ["ISRI","Arabic","stemmer","based","on","algorithm",":","Arabic","Stemming","without","a","root","dictionary",".","Information","Science","Research","Institute",".","University","of","Nevada",",","Las","Vegas",",","USA",".","A","few","minor","modifications","have","been","made","to","ISRI","basic","algorithm",".","See","the","source","code","of","this","module","for","more","information",".","isri.stem","(","token",")","returns","Arabic","root","for","the","given","token",".","The","ISRI","Stemmer","requires","that","all","tokens","have","Unicode","string","types",".","If","you","use","Python","IDLE","on","Arabic","Windows","you","have","to","decode","text","first","using","Arabic","'1256","'","coding","."]
docstr: normalization:
  num=1  normalize diacritics
  num=2  normalize initial hamza
  num=3  both 1&2
docstr_tok: ["normalization",":","num=1","normalize","diacritics","num=2","normalize","initial","hamza","num=3","both","1","&","2"]
code: def norm(self, num):
      """
      normalization:
      num=1  normalize diacritics
      num=2  normalize initial hamza
      num=3  both 1&2
      """
      self.k = num
  
      if self.k == 1:
          self.stm = self.re_short_vowels.sub("", self.stm)
          return self.stm
      elif self.k == 2:
          self.stm = self.re_intial_hamza.sub("\u0627", self.stm)
          return self.stm
      elif self.k == 3:
          self.stm = self.re_short_vowels.sub("", self.stm)
          self.stm = self.re_intial_hamza.sub("\u0627", self.stm)
          return self.stm
  
file_path: whoosh/src/whoosh/lang/isri.py
imports: from __future__ import unicode_literals
  import re
label_desc: Use image node_id 3 for calling the ISRIStemmer obj's underlying member method code with example usage: obj.norm(num) and returns: self, self, self