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: process length six patterns and extract length three roots
docstr_tok: ["process","length","six","patterns","and","extract","length","three","roots"]
code: def pro_w6(self):
      """process length six patterns and extract length three roots"""
      if (self.stm.startswith("\u0627\u0633\u062a")) or (
          self.stm.startswith("\u0645\u0633\u062a")
      ):  #   مستفعل   -    استفعل
          self.stm = self.stm[3:]
          return self.stm
      elif (
          self.stm[0] == "\u0645"
          and self.stm[3] == "\u0627"
          and self.stm[5] == "\u0629"
      ):  #     مفعالة
          self.stm = self.stm[1:3] + self.stm[4]
          return self.stm
      elif (
          self.stm[0] == "\u0627"
          and self.stm[2] == "\u062a"
          and self.stm[4] == "\u0627"
      ):  #     افتعال
          self.stm = self.stm[1] + self.stm[3] + self.stm[5]
          return self.stm
      elif (
          self.stm[0] == "\u0627"
          and self.stm[3] == "\u0648"
          and self.stm[2] == self.stm[4]
      ):  #    افعوعل
          self.stm = self.stm[1] + self.stm[4:]
          return self.stm
      elif (
          self.stm[0] == "\u062a"
          and self.stm[2] == "\u0627"
          and self.stm[4] == "\u064a"
      ):  #     تفاعيل    new pattern
          self.stm = self.stm[1] + self.stm[3] + self.stm[5]
          return self.stm
      else:
          self.suf1()  # do - normalize short sufix
          if len(self.stm) == 6:
              self.pre1()  # do - normalize short prefix
          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 11 for calling the ISRIStemmer obj's underlying member method code with example usage: obj.pro_w6() and returns: self, self, self, self, self, self