Initial commit

Solutions/3_8/stock.py

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+# stock.py
+
+class Stock:
+    __slots__ = ('name','_shares','_price')
+    _types = (str, int, float)
+    def __init__(self, name, shares, price):
+        self.name = name
+        self.shares = shares
+        self.price = price
+
+    def __repr__(self):
+        # Note: The !r format code produces the repr() string
+        return f'{type(self).__name__}({self.name!r}, {self.shares!r}, {self.price!r})'
+
+    def __eq__(self, other):
+        return isinstance(other, Stock) and ((self.name, self.shares, self.price) ==
+                (other.name, other.shares, other.price))
+
+    @classmethod
+    def from_row(cls, row):
+        values = [func(val) for func, val in zip(cls._types, row)]
+        return cls(*values)
+
+    @property
+    def shares(self):
+        return self._shares
+    @shares.setter
+    def shares(self, value):
+        if not isinstance(value, self._types[1]):
+            raise TypeError(f'Expected {self._types[1].__name__}')
+        if value < 0:
+            raise ValueError('shares must be >= 0')
+        self._shares = value
+
+    @property
+    def price(self):
+        return self._price
+    @price.setter
+    def price(self, value):
+        if not isinstance(value, self._types[2]):
+            raise TypeError(f'Expected {self._types[2].__name__}')
+        if value < 0:
+            raise ValueError('price must be >= 0')
+        self._price = value
+
+    @property
+    def cost(self):
+        return self.shares * self.price
+
+    def sell(self, nshares):
+        self.shares -= nshares
+
+# Sample
+if __name__ == '__main__':
+    import tableformat
+    import reader
+    from tableformat import (
+        print_table,
+        create_formatter,
+        TextTableFormatter,
+        ColumnFormatMixin,
+        UpperHeadersMixin
+        )
+
+    portfolio = reader.read_csv_as_instances('../../Data/portfolio.csv', Stock)
+
+    class PortfolioFormatter(ColumnFormatMixin, TextTableFormatter):
+        formats = ['%s','%d','%0.2f']
+
+    formatter = PortfolioFormatter()
+    print_table(portfolio,['name','shares','price'], formatter)
+
+    class PortfolioFormatter(UpperHeadersMixin, TextTableFormatter):
+        pass
+
+    formatter = PortfolioFormatter()
+    print_table(portfolio, ['name','shares','price'], formatter)
+
+    # Factory function version
+    formatter = create_formatter('text', column_formats=['%s','%d','%0.2f'])
+    print_table(portfolio, ['name','shares','price'], formatter)
+
+    formatter = create_formatter('text', upper_headers=True)
+    print_table(portfolio, ['name','shares','price'], formatter)