title: Python ISRIStemmer for Arabic text
body: <p>I am running the following code on IDLE(Python) and I want to enter Arabic string and get the stemming for it but actually it doesn't work</p>
  <pre><code>&gt;&gt;&gt; from nltk.stem.isri import ISRIStemmer
  &gt;&gt;&gt; st = ISRIStemmer()
  &gt;&gt;&gt; w= 'حركات'
  &gt;&gt;&gt; join = w.decode('Windows-1256')
  &gt;&gt;&gt; print st.stem(join).encode('Windows-1256').decode('utf-8')
  </code></pre>
  <p>The result of running it is the same text in w which is 'حركات' which is not the stem</p>
  <p>But when do the following:</p>
  <pre><code>&gt;&gt;&gt; print st.stem(u'اعلاميون')
  </code></pre>
  <p>The result succeeded and returns the stem which is 'علم'</p>
  <p>Why passing some words to stem() function doesn't return the stem?</p>