《python基础教程》答案（第七章）_头歌python第七章作业答案

《python基础教程》答案（第七章）

Fridge.py

# created by swy
"""
solutions to beginning python
"""


class Fridge:
    def __init__(self, items={
   }):
        """
        Optionally pass in an initial dictionary of items
        :param items:
        """
        if type(items) != type({
   }):
            raise TypeError("Fridge requires a dictionary but was given %s" % type(items))
        self.items = items
        return

    def __add_multi(self, food_name, quantity):
        if food_name not in self.items:
            self.items[food_name] = 0

        self.items[food_name] = self.items[food_name] + quantity

    def add_one(self, food_name):
        if type(food_name) != type(""):
            raise TypeError("add_one requires a string, given a %s" % type(food_name))
        else:
            self.__add_multi(food_name, 1)

        return True

    def add_many(self, food_dict):
        if type(food_dict) != type({
   }):
            raise TypeError("add_many requires a dictionary, got a %s" % food_dict)
        for item in food_dict.keys():
            self.__add_multi(item, food_dict[item])
        return

    def has(self, food_name, quantity=1):
        return self.has_various({
   food_name: quantity})

    def has_various(self, foods):
        try:
            for food in foods.keys():
                if self.items[food] < foods[food]:
                    return False
            return True
        except KeyError:
            return False

    def __get_multi(self, food_name, quantity):
        try:
            if self.items[food_name] is None:
                return False
            if quantity > self.items[food_name]:
                return False
            self.items[food_name] = self.items[food_name] - quantity
        except KeyError:
            return False
        return quantity

    def get_one(self, food_name):
        if type(food_name) != type(""):
            raise TypeError("get_one requires a string, given a %s" % type(food_name))
        else:
            result = self.__get_multi(food_name, 1
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