38 lines
925 B
Python
38 lines
925 B
Python
"""
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A line item for a bulk food order has description, weight and price fields.
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A ``subtotal`` method gives the total price for that line item::
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>>> raisins = LineItem('Golden raisins', 10, 6.95)
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>>> raisins.weight, raisins.description, raisins.price
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(10, 'Golden raisins', 6.95)
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>>> raisins.subtotal()
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69.5
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But, without validation, these public attributes can cause trouble::
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# BEGIN LINEITEM_PROBLEM_V1
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>>> raisins = LineItem('Golden raisins', 10, 6.95)
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>>> raisins.subtotal()
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69.5
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>>> raisins.weight = -20 # garbage in...
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>>> raisins.subtotal() # garbage out...
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-139.0
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# END LINEITEM_PROBLEM_V1
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"""
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# BEGIN LINEITEM_V1
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class LineItem:
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def __init__(self, description, weight, price):
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self.description = description
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self.weight = weight
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self.price = price
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def subtotal(self):
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return self.weight * self.price
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# END LINEITEM_V1
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