test: use pytest parametrize mark

tests/test_fetch_holidays.py

@@ -1,8 +1,10 @@
 """Test module `fetch_holidays`.  """
 import json
-import sys
 
-from fetch_holidays import CustomJSONEncoder, DescriptionParser, get_paper_urls, get_rules, get_paper
+import pytest
+
+from fetch_holidays import (CustomJSONEncoder, DescriptionParser, get_paper,
+                            get_paper_urls, get_rules)
 
 from .filetools import _file_path
 
@@ -15,8 +17,11 @@ def test_get_paper_urls():
 
 
 def test_get_rules():
-    assert(list(get_rules(get_paper('http://www.gov.cn/zhengce/content/2019-03/22/content_5375877.htm')))
-           == [('劳动节', '2019年5月1日至4日放假调休，共4天。4月28日（星期日）、5月5日（星期日）上班。')])
+    assert (
+        list(get_rules(get_paper(
+            'http://www.gov.cn/zhengce/content/2019-03/22/content_5375877.htm')))
+        == [('劳动节',
+             '2019年5月1日至4日放假调休，共4天。4月28日（星期日）、5月5日（星期日）上班。')])
 
 
 def _normalize(iterable):
@@ -24,20 +29,14 @@ def _normalize(iterable):
                   key=lambda x: x['date'])
 
 
-def _generate_tests():
+def _description_parsing_cases():
     with open(_file_path('description_parsing_cases.json'), 'r', encoding='utf-8', ) as f:
-        cases = json.load(f)
-
-    def create_test(case):
-        def _test():
-            year, description, expected = case['year'], case['description'], case['expected']
-            assert _normalize(DescriptionParser(
-                description, year).parse()) == _normalize(expected), case
-        return _test
-
-    for index, case in enumerate(cases, 1):
-        setattr(sys.modules[__name__],
-                f'test_description_parser_{index}', create_test(case))
+        return json.load(f)
 
 
-_generate_tests()
+@pytest.mark.parametrize('case', _description_parsing_cases())
+def test_parse_description(case):
+
+    year, description, expected = case['year'], case['description'], case['expected']
+    assert _normalize(DescriptionParser(
+        description, year).parse()) == _normalize(expected), case