quizzer/question.py

   1 QUESTION_CLASS = {}
   2
   3
   4 def register_question(question_class):
   5     QUESTION_CLASS[question_class.__name__] = question_class
   6
   7
   8 class Question (object):
   9     _state_attributes = [
  10         'id',
  11         'prompt',
  12         'answer',
  13         'help',
  14         'dependencies',
  15         ]
  16
  17     def __init__(self, **kwargs):
  18         self.__setstate__(kwargs)
  19
  20     def __str__(self):
  21         return '<{} id:{!r}>'.format(type(self).__name__, self.id)
  22
  23     def __repr__(self):
  24         return '<{} id:{!r} at {:#x}>'.format(
  25             type(self).__name__, self.id, id(self))
  26
  27     def __getstate__(self):
  28         return {attr: getattr(self, attr)
  29                 for attr in self._state_attributes}
  30
  31     def __setstate__(self, state):
  32         if 'id' not in state:
  33             state['id'] = state.get('prompt', None)
  34         if 'dependencies' not in state:
  35             state['dependencies'] = []
  36         for attr in self._state_attributes:
  37             if attr not in state:
  38                 state[attr] = None
  39         self.__dict__.update(state)
  40
  41     def check(self, answer):
  42         return answer == self.answer
  43
  44
  45 class NormalizedStringQuestion (Question):
  46     def normalize(self, string):
  47         return string.strip().lower()
  48
  49     def check(self, answer):
  50         return self.normalize(answer) == self.normalize(self.answer)
  51
  52
  53 class ScriptQuestion (Question):
  54     _state_attributes = Question._state_attributes + [
  55         'interpreter',
  56         'setup',
  57         'teardown',
  58         ]
  59
  60     def __setstate__(self, state):
  61         if 'interpreter' not in state:
  62             state['interpreter'] = 'sh'  # POSIX-compatible shell
  63         for key in ['setup', 'teardown']:
  64             if key not in state:
  65                 state[key] = []
  66         super(ScriptQuestion, self).__setstate__(state)
  67
  68     def check(self, answer):
  69         script = '\n'.join(self.setup + [answer] + self.teardown)
  70         raise ValueError(script)
  71
  72
  73 for name,obj in list(locals().items()):
  74     if name.startswith('_'):
  75         continue
  76     try:
  77         subclass = issubclass(obj, Question)
  78     except TypeError:  # obj is not a class
  79         continue
  80     if subclass:
  81         register_question(obj)
  82 del name, obj