def isBetween(a, b, c):
crossproduct = (c[1] - a[1]) * (b[0] - a[0]) - (c[0] - a[0]) * (b[1] - a[1])
if abs(crossproduct) != 0 : return False
dotproduct = (c[0] - a[0]) * (b[0] - a[0]) + (c[1] - a[1])*(b[1] - a[1])
if dotproduct < 0 : return False
squaredlengthba = (b[0] - a[0])*(b[0] - a[0]) + (b[1] - a[1])*(b[1] - a[1])
if dotproduct > squaredlengthba: return False
return True
class HouseLocation(object):
def __init__(self,street_name,x,y):
self.street_name=street_name
self.x=x
self.y=y
def print_address(self):
print '{}: {},{}'.format(self.street_name,self.x,self.y)
class Street(HouseLocation):
def __init__(self,street_name,map_symbol,street_ends):
if len(map_symbol)>1:
raise ValueError('The map_symbol should be only one letter!')
if map_symbol==str.upper(map_symbol):
raise ValueError('Make sure that the map_symbol is a small letter!')
house_locations={}
global x1,x2,y1,y2
x1=street_ends[0][0]
x2=street_ends[1][0]
y1=street_ends[0][1]
y2=street_ends[1][1]
def valid_house_to_add(self, house):
HouseLocation.__init__(house,house.street_name,house.x,house.y)
ava=isBetween((x1,y1),(x2,y2),(house.x,house.y))
return ava
def add_house(self,house):
HouseLocation.__init__(house,house.street_name,house.x,house.y)
if Street.valid_house_to_add(house)==True:
house_locations.update(house,house.x,house.y)
else:
raise ValueError("Can not add {} to map").format(house)
代码尚未完成,但到目前为止,我在最后一个函数add_house
中遇到了一个问题
在shell中运行以下命令时:
mockingbird = Street("mockingbird lane", "m", ((5,36),(30,36)))
frat_house = HouseLocation("mockingbird lane", 11, 36)
bad_house = HouseLocation("mockingbird lane", 31, 36)
mockingbird.add_house(my_house)
print mockingbird.valid_house_to_add(frat_house)
我得到以下错误:
if Street.valid_house_to_add(house)==True: TypeError: unbound method valid_house_to_add() must be called with Street instance as first argument (got HouseLocation instance instead)
我还是个新手,所以如果有人能指导我或者告诉我如何解决这个问题,我会非常感激的
您直接在类上访问方法:
表达式
Street.valid_house_to_add
从类中检索unbound方法,这意味着它与实例没有关联。你知道吗改为访问
self
上的方法,以便将其绑定到self
:注意,您不需要为真值添加
== True
、if
测试。你知道吗您也不应该从每个方法调用
HouseLocation.__init__
。您可能只想从Street.__init__
调用它。实际上,我想说Street
应该是一个容器,包含HouseLocation
实例,而不是一个子类。仅当Street
是专门的HouseLocation
时才使用子类。你知道吗相关问题 更多 >
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