Greek stemmer bug fix

.github/workflows/run-tests.yml

@@ -12,7 +12,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-latest"]
-        python-version: ["3.5", "3.6", "3.7", "3.8", "3.9", "3.10"]
+        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
         include:
 #          - os: "windows-2022"
 #            python-version: "3.10"

CONTRIBUTING.md

@@ -14,7 +14,7 @@ with your code. Nothing is written in stone but please try to respect them.
 4. Please **respect the code style**. I don't want to set specific strict rules here because I think it's 
    possible to respect style from all the code around. For example you will not use `'` for strings 
    when you see that the code uses `"` ...
-5. Make sure you have Python 3.5+ installed. Also, **Python 2.7/3.4** and maybe older versions work but since 
+5. Make sure you have Python 3.6+ installed. Also, **Python 2.7/3.4** and maybe older versions work but since 
    they reached end-of-life you could have difficulties with the transitive dependencies that dropped the support 
    already. Then, install all the required dependencies and run the tests:
 

README.md

@@ -13,7 +13,7 @@ There is a [good chance](docs/index.md#Tokenizer) it is. But if not it is [not t
 
 ## Installation
 
-Make sure you have [Python](http://www.python.org/) 3.5+ and
+Make sure you have [Python](http://www.python.org/) 3.6+ and
 [pip](https://crate.io/packages/pip/)
 ([Windows](http://docs.python-guide.org/en/latest/starting/install/win/),
 [Linux](http://docs.python-guide.org/en/latest/starting/install/linux/))

setup.py

@@ -109,6 +109,7 @@
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
         "Programming Language :: Python :: Implementation :: CPython",
     ],
 )

sumy/nlp/stemmers/greek.py

@@ -31,7 +31,7 @@ def stem_word(word):
     for tag in _TOTAL_TAGS:
         try:
             stemmed = gr_stemmer.stem_word(word.lower(), tag)
-            if stemmed[-1].upper() in _CONSONANTS:
+            if stemmed and stemmed[-1].upper() in _CONSONANTS:
                 stem_candidates.add(stemmed)
         except (TypeError, ValueError):
             pass

tests/test_stemmers.py

@@ -44,3 +44,10 @@ def test_slovak_stemmer():
 
     assert type(actual) is type(expected)
     assert expected.__dict__ == actual.__dict__
+
+
+def test_greek_stemmer():
+    greek_stemmer = Stemmer("greek")
+    # The first assert covers the empty stem case.
+    assert "οτ" == greek_stemmer("όταν")
+    assert "εργαζ" == greek_stemmer("εργαζόμενος")