44 lines
936 B
Markdown
44 lines
936 B
Markdown
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# Exercise 6.1 - Solution
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## (a) Simplified Structures
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```python
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# structure.py
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class Structure:
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_fields = ()
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def __init__(self, *args):
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if len(args) != len(self._fields):
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raise TypeError('Expected %d arguments' % len(self._fields))
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for name, arg in zip(self._fields,args):
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setattr(self, name, arg)
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```
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## (b) Making a Useful Representation
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[source, python]
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```
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class Structure:
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...
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def __repr__(self):
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return '%s(%s)' % (type(self).__name__,
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', '.join(repr(getattr(self, name)) for name in self._fields))
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```
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## (c) Restricting Attribute Names
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[source, python]
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```
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class Structure:
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...
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def __setattr__(self, name, value):
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if name.startswith('_') or name in self._fields:
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super().__setattr__(name, value)
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else:
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raise AttributeError('No attribute %s' % name)
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```
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[Back](ex6_1.md)
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