40 lines
875 B
Markdown
40 lines
875 B
Markdown
# Exercise 5.4 - Solution
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```python
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# typedproperty.py
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def typedproperty(name, expected_type):
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private_name = '_' + name
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@property
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def value(self):
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return getattr(self, private_name)
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@value.setter
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def value(self, val):
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if not isinstance(val, expected_type):
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raise TypeError(f'Expected {expected_type}')
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setattr(self, private_name, val)
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return value
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String = lambda name: typedproperty(name, str)
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Integer = lambda name: typedproperty(name, int)
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Float = lambda name: typedproperty(name, float)
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# Example
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if __name__ == '__main__':
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class Stock:
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name = String('name')
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shares = Integer('shares')
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price = Float('price')
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def __init__(self, name, shares, price):
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self.name = name
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self.shares = shares
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self.price = price
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```
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[Back](ex5_4.md)
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