Я новичок в python, и у меня возникла небольшая проблема, чтобы понять и использовать итератор в классе.
def findLargest(shapes):
"""
Returns a tuple containing the elements of ShapeSet with the
largest area.
shapes: ShapeSet
"""
bestName = shapes.List[:]
for i in shapes.List:
if i.cmp(i+1)== -1:
bestName.remove(memo)
if i.cmp(i+1)==1:
bestName.remove(i)
for element in bestName:
stringout=''
stringout= stringout + 'Element ' + str(element.name) + ' with an area of ' + str(element.area()) + ', '
return stringout
Итак, я хочу сравнить область списка элементов и получитькортеж элементов с самой большой площадью.Моя задача - сравнить мой элемент «i» с элементом «i + 1».Я не знаю, как это назвать.Для итерации я определяю метод iter и next () для итерации по фигурам. Список
Кто-то может мне помочь или, может быть, сказать мне, что будет хорошим способом реализовать эту функцию.
Спасибо
полный код ниже
from string import *
class Shape(object):
def area(self):
raise AttributeException("Subclasses should override this method.")
def cmp(self, other):
if type(other) != Shape and type(other) !=Square and type(other) !=Triangle and type(other) !=Circle:
return 'Not a shape!'
if self.area > other.area:
return 1
if self.area == other.area:
return 0
if self.area < other.area:
return -1
class Square(Shape):
def __init__(self, h, name):
"""
h: length of side of the square
"""
self.side = float(h)
self.name = name
def area(self):
"""
Returns area of the square
"""
return self.side**2
def __str__(self):
return 'Square with side ' + str(self.side)
def __eq__(self, other):
"""
Two squares are equal if they have the same dimension.
other: object to check for equality
"""
return type(other) == Square and self.side == other.side
class Circle(Shape):
def __init__(self, radius, name):
"""
radius: radius of the circle
"""
self.radius = float(radius)
self.name = name
def area(self):
"""
Returns approximate area of the circle
"""
return 3.14159*(self.radius**2)
def __str__(self):
return 'Circle with radius ' + str(self.radius)
def __eq__(self, other):
"""
Two circles are equal if they have the same radius.
other: object to check for equality
"""
return type(other) == Circle and self.radius == other.radius
# Problem 1: Create the Triangle class
class Triangle(Shape):
def __init__(self, base, height, name):
self.base= float(base)
self.height=float(height)
self.name = name
def area (self):
area=float(self.base*self.height)/2
return area
def __str__(self):
return 'Triangle with a base ' + str(self.base) +' and height ' + str(self.height)
def __eq__ (self, other):
return type(other)==Triangle and self.base == other.base and self.height == other.height
#Problem 2: Create the ShapeSet class
class ShapeSet:
def __init__(self):
"""
Initialize any needed variables
"""
self.List = []
self.index=0
def addShape(self, sh):
"""
Add shape sh to the set; no two shapes in the set may be
identical
sh: shape to be added
"""
if self==[]:
self.List.append(sh)
else:
for shape in self.List:
if shape == sh:
return 'This shape already exist'
if shape.area == sh.area and type(shape) == type(sh):
return 'This shape already exist'
self.List.append(sh)
def __iter__(self):
"""
Return an iterator that allows you to iterate over the set of
shapes, one shape at a time
"""
return self
def next():
if self.index>len(self.List-1):
StopIteration
else:
self.index+=1
return self.List[self.index-1]
def __str__(self):
"""
Return the string representation for a set, which consists of
the string representation of each shape, categorized by type
(circles, then squares, then triangles)
"""
triangleList=[]
squareList=[]
circleList=[]
if self.List == []:
return 'The set is empty'
else:
for element in self.List:
if type(element)==Triangle:
triangleList.append(element.name)
elif type(element)==Square:
squareList.append(element.name)
elif type(element)==Circle:
circleList.append(element.name)
return 'circles: %s, square: %s, triangle: %s' % (circleList, squareList, triangleList)