59 lines
1.1 KiB
Markdown
59 lines
1.1 KiB
Markdown
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# Exercise 6.3 - Solution
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```python
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# structure.py
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import sys
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import inspect
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class Structure:
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_fields = ()
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@staticmethod
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def _init():
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locs = sys._getframe(1).f_locals
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self = locs.pop('self')
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for name, val in locs.items():
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setattr(self, name, val)
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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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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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@classmethod
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def set_fields(cls):
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sig = inspect.signature(cls)
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cls._fields = tuple(sig.parameters)
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```
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Here is the `Stock` class in progress:
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```python
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# stock.py
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from structure import Structure
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class Stock(Structure):
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def __init__(self, name, shares, price):
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self._init()
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@property
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def cost(self):
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return self.shares * self.price
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def sell(self, nshares):
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self.shares -= nshares
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Stock.set_fields()
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```
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[Back](ex6_3.md)
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