Question

我正在努力解决这个问题。我收到了错误。我无法理解在哪里修复

class Location(object):
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def move(self, deltaX, deltaY):
        return Location(self.x + deltaX, self.y + deltaY)

    def getX(self):
        return self.x

    def getY(self):
        return self.y

    def dist_from(self, other):
        xDist = self.x - other.x
        yDist = self.y - other.y
        return (xDist ** 2 + yDist ** 2) ** 0.5

    def __eq__(self, other):
        return (self.x == other.x and self.y == other.y)

    def __str__(self):
        return '<' + str(self.x) + ',' + str(self.y) + '>'


    class Campus(object):
    def __init__(self, center_loc):
        self.center_loc = center_loc

    def __str__(self):
        return str(self.center_loc)





class MITCampus(Campus):

    """ A MITCampus is a Campus that contains tents """

    def __init__(self, center_loc, tent_loc=Location(0, 0)):
        """ Assumes center_loc and tent_loc are Location objects
        Initializes a new Campus centered at location center_loc
        with a tent at location tent_loc """
        # Your code here
        self.center_loc = center_loc
        self.tent_loc = tent_loc

    def add_tent(self, new_tent_loc):
        """ Assumes new_tent_loc is a Location
        Adds new_tent_loc to the campus only if the tent is at least 0.5 distance
        away from all other tents already there. Campus is unchanged otherwise.
        Returns True if it could add the tent, False otherwise. """
        # Your code here
        try:
            self.tent_loc[object] += 1
        except:
            self.tent_loc[object] = 1
        return new_tent_loc in self.tent_loc

    def remove_tent(self, tent_loc):
        """ Assumes tent_loc is a Location
        Removes tent_loc from the campus.
        Raises a ValueError if there is not a tent at tent_loc.
        Does not return anything """
        # Your code here
        if tent_loc not in self.tent_loc:
            return
        self.tent_loc[tent_loc] -= 1
        if self.tent_loc[tent_loc] < 1:
            del (self.tent_loc[tent_loc])

例如，如果c = MITCampus(Location(1,2))则执行以下命令序列：

c.add_tent(Location(2,3))应该返回True

c.add_tent(Location(0,0))应该返回False

c.add_tent(Location(2,3))应该返回False

c.get_tents()应该返回['<0,0>', '<1,2>', '<2,3>']

我得到的是错误：The class named 'MITCampus' should define a method named get_tents.

Answer 1

def add_tent(self, new_tent_loc):
    """ Assumes new_tent_loc is a Location
    Adds new_tent_loc to the campus only if the tent is at least 0.5 distance
    away from all other tents already there. Campus is unchanged otherwise.
    Returns True if it could add the tent, False otherwise. """
    # Your code here
    try:
        self.tent_loc[object] += 1
    except:
        self.tent_loc[object] = 1
    return new_tent_loc in self.tent_loc

这不起作用：object是内置函数，不能用作序列索引。

Answer 2

找到快速解决方案比解释所有内容更快;）

class Location(object):
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def move(self, deltaX, deltaY):
        return Location(self.x + deltaX, self.y + deltaY)

    def getX(self):
        return self.x

    def getY(self):
        return self.y

    def dist_from(self, other):
        xDist = self.x - other.x
        yDist = self.y - other.y
        dist = (xDist ** 2 + yDist ** 2) ** 0.5
        return dist

    def __eq__(self, other):
        return (self.x == other.x and self.y == other.y)

    def __str__(self):
        return '<' + str(self.x) + ',' + str(self.y) + '>'


class Campus(object):
    def __init__(self, center_loc):
        self.center_loc = center_loc

    def __str__(self):
        return str(self.center_loc)


class MITCampus(Campus):

    """ A MITCampus is a Campus that contains tents """

    def __init__(self, center_loc, tent_loc=Location(0, 0)):
        """ Assumes center_loc and tent_loc are Location objects
        Initializes a new Campus centered at location center_loc
        with a tent at location tent_loc """
        # Your code here
        assert isinstance(center_loc, Location)
        assert isinstance(tent_loc, Location)
        self.center_loc = center_loc
        self.tent_locs = [tent_loc]

    def add_tent(self, new_tent_loc):
        """ Assumes new_tent_loc is a Location
        Adds new_tent_loc to the campus only if the tent is at least 0.5 distance
        away from all other tents already there. Campus is unchanged otherwise.
        Returns True if it could add the tent, False otherwise. """
        # Your code here
        assert isinstance(new_tent_loc, Location)
        added = False
        for tent_loc in self.tent_locs:
            if tent_loc.dist_from(new_tent_loc) <= 0.5:
                break
        else:
            self.tent_locs.append(new_tent_loc)
            added = True
        return added

    def remove_tent(self, tent_loc):
        """ Assumes tent_loc is a Location
        Removes tent_loc from the campus.
        Raises a ValueError if there is not a tent at tent_loc.
        Does not return anything """
        # Your code here
        assert isinstance(tent_loc, Location)
        position = self.tent_locs.index(tent_loc)
        del self.tent_locs[position]

    def get_tents(self):
        return sorted([str(x) for x in [self.center_loc] + self.tent_locs])


c = MITCampus(Location(1, 2))
assert c.add_tent(Location(2, 3))  # -> True
assert not c.add_tent(Location(0, 0))  # -> Flase
assert not c.add_tent(Location(2, 3))  # -> False
assert c.get_tents() == ['<0,0>', '<1,2>', '<2,3>']
try:
    c.remove_tent(Location(6, 6))
    print "removal failed"
except ValueError:
    # Expected behaviour
    pass
c.remove_tent(Location(2, 3))
assert c.get_tents() == ['<0,0>', '<1,2>']

希望这有帮助！想想我的声誉;）

无法解决这个问题

2 个答案: