Python中的继承和超级类不起作用

Question

早上好

我是一个A级计算机科学教师，随着他们的预科材料考试即将到来，他们正忙着努力工作。在

我不教编程方面的课程，集中在理论上，他们的编程老师已经病休了一段时间，所以我正在尽我所能去支持高端编程。在

他们在Python中的预发布材料是基于一个狐狸和兔子的游戏，其中一个学生正在尝试创建一个名为“GiantWarren”的类，它继承了warren的属性和功能，但这是一个更大的实例。在

他的代码在下面，他使用'super'来尝试继承warren的函数，但是除非他复制并粘贴这些函数，否则它将无法工作。任何关于如何获得超常工作的帮助都会非常感谢，不仅是我，我的学生也会：

注意-沃伦是228号线，詹特沃伦是351号线

#Skeleton Program code for the AQA A Level Paper 1 2017 examination
#this code should be used in conjunction with the Preliminary Material
#written by the AQA Programmer Team
#developed in the Python 3.4.1 programming environment

import enum
import random
import math

class Location:
  def __init__(self):
    self.Fox = None
    self.Warren = None

class Simulation:
  def __init__(self, LandscapeSize, InitialWarrenCount, InitialFoxCount, Variability, FixedInitialLocations):
    self.__ViewRabbits = ""
    self.__TimePeriod = 0
    self.__WarrenCount = 0
    self.__FoxCount = 0
    self.__ShowDetail = False
    self.__LandscapeSize = LandscapeSize
    self.__Variability = Variability
    self.__FixedInitialLocations = FixedInitialLocations
    self.__Landscape = []
    for Count1 in range (self.__LandscapeSize):
      LandscapeRow = []
      for Count2 in range (self.__LandscapeSize):
        LandscapeLocation = None
        LandscapeRow.append(LandscapeLocation)
      self.__Landscape.append(LandscapeRow)
    self.__CreateLandscapeAndAnimals(InitialWarrenCount, InitialFoxCount, self.__FixedInitialLocations)
    self.__DrawLandscape()
    MenuOption = 0
    while (self.__WarrenCount > 0 or self.__FoxCount > 0) and MenuOption != 5:
      print()
      print("0. Advance 10 time periods hiding detail")
      print("1. Advance to next time period showing detail")
      print("2. Advance to next time period hiding detail")
      print("3. Inspect fox")
      print("4. Inspect warren")
      print("5. Exit")
      print()
      try:
        MenuOption = int(input("Select option: "))
      except:
        print("What you have entered is not an integer. Try again")
      if MenuOption == 0:
        for a in range(1, 11):
          self.__TimePeriod += 1
          self.__ShowDetail = False
          self.__AdvanceTimePeriod()
      if MenuOption == 1:
        self.__TimePeriod += 1
        self.__ShowDetail = True
        self.__AdvanceTimePeriod()
      if MenuOption == 2:
        self.__TimePeriod += 1
        self.__ShowDetail = False
        self.__AdvanceTimePeriod()
      if MenuOption == 3:
        x = self.__InputCoordinate("x")
        y = self.__InputCoordinate("y")
        if not self.__Landscape[x][y].Fox is None:
          self.__Landscape[x][y].Fox.Inspect()
      if MenuOption == 4:
        x = self.__InputCoordinate("x")
        y = self.__InputCoordinate("y")
        if not self.__Landscape[x][y].Warren is None:
          self.__Landscape[x][y].Warren.Inspect()
          self.__ViewRabbits = input("View individual rabbits (y/n)? ")
          if self.__ViewRabbits == "y":
            self.__Landscape[x][y].Warren.ListRabbits()
    input()

  def __InputCoordinate(self, CoordinateName):
    Coordinate = int(input("  Input " + CoordinateName + " coordinate:"))
    return Coordinate

  def __AdvanceTimePeriod(self):
    NewFoxCount = 0
    if self.__ShowDetail:
      print()
    for x in range (0, self.__LandscapeSize):
      for y in range (0, self.__LandscapeSize):
        if not self.__Landscape[x][y].Warren is None:
          if self.__ShowDetail:
            print("Warren at (", x, ",", y, "):", sep = "")
            print("  Period Start: ", end = "")
            self.__Landscape[x][y].Warren.Inspect()
          if self.__FoxCount > 0:
            self.__FoxesEatRabbitsInWarren(x, y)
          if self.__Landscape[x][y].Warren.NeedToCreateNewWarren():
            self.__CreateNewWarren()
          self.__Landscape[x][y].Warren.AdvanceGeneration(self.__ShowDetail)
          if self.__ShowDetail:
            print("  Period End: ", end = "")
            self.__Landscape[x][y].Warren.Inspect()
            input()
          if self.__Landscape[x][y].Warren.WarrenHasDiedOut():
            self.__Landscape[x][y].Warren = None
            self.__WarrenCount -= 1
    for x in range (0, self.__LandscapeSize):
      for y in range (0, self.__LandscapeSize):
        if not self.__Landscape[x][y].Fox is None:
          if self.__ShowDetail:
            print("Fox at (", x, ",", y, "): ", sep = "")
          self.__Landscape[x][y].Fox.AdvanceGeneration(self.__ShowDetail)
          if self.__Landscape[x][y].Fox.CheckIfDead():
            self.__Landscape[x][y].Fox = None
            self.__FoxCount -= 1
          else:
            if self.__Landscape[x][y].Fox.ReproduceThisPeriod():
              if self.__ShowDetail:
                print("  Fox has reproduced. ")
              NewFoxCount += 1
            if self.__ShowDetail:
              self.__Landscape[x][y].Fox.Inspect()
            self.__Landscape[x][y].Fox.ResetFoodConsumed()
    if NewFoxCount > 0:
      if self.__ShowDetail:
        print("New foxes born: ")
      for f in range (0, NewFoxCount):
        self.__CreateNewFox()
    if self.__ShowDetail:
      input()
    self.__DrawLandscape()
    print()

  def __CreateLandscapeAndAnimals(self, InitialWarrenCount, InitialFoxCount, FixedInitialLocations):
    for x in range (0, self.__LandscapeSize):
      for y in range (0, self.__LandscapeSize):
        self.__Landscape[x][y] = Location()
    if FixedInitialLocations:
      self.__Landscape[1][1].Warren = Warren(self.__Variability, 38)
      self.__Landscape[2][8].Warren = Warren(self.__Variability, 80) 
      self.__Landscape[9][7].Warren = Warren(self.__Variability, 20)
      self.__Landscape[10][3].Warren = Warren(self.__Variability, 52)
      self.__Landscape[13][4].Warren = Warren(self.__Variability, 67)
      self.__Landscape[11][4].Warren = GiantWarren(self.__Variability, 115)
      self.__WarrenCount = 6
      self.__Landscape[2][10].Fox = Fox(self.__Variability)
      self.__Landscape[6][1].Fox = Fox(self.__Variability)
      self.__Landscape[8][6].Fox = Fox(self.__Variability)
      self.__Landscape[11][13].Fox = Fox(self.__Variability)
      self.__Landscape[12][4].Fox = Fox(self.__Variability)
      self.__FoxCount = 5
    else:
      for w in range (0, InitialWarrenCount):
        self.__CreateNewWarren()
      for f in range (0, InitialFoxCount):
        self.__CreateNewFox()

  def __CreateNewWarren(self):
    x = random.randint(0, self.__LandscapeSize - 1)
    y = random.randint(0, self.__LandscapeSize - 1)
    while not self.__Landscape[x][y].Warren is None:
      x = random.randint(0, self.__LandscapeSize - 1)
      y = random.randint(0, self.__LandscapeSize - 1)
    if self.__ShowDetail:
      print("New Warren at (", x, ",", y, ")", sep = "")
    self.__Landscape[x][y].Warren = Warren(self.__Variability)
    self.__WarrenCount += 1

  def __CreateNewFox(self):
    x = random.randint(0, self.__LandscapeSize - 1)
    y = random.randint(0, self.__LandscapeSize - 1)
    while not self.__Landscape[x][y].Fox is None:
      x = random.randint(0, self.__LandscapeSize - 1)
      y = random.randint(0, self.__LandscapeSize - 1)
    if self.__ShowDetail:
      print("  New Fox at (", x, ",", y, ")", sep = "")
    self.__Landscape[x][y].Fox = Fox(self.__Variability)
    self.__FoxCount += 1

  def __FoxesEatRabbitsInWarren(self, WarrenX, WarrenY):
    RabbitCountAtStartOfPeriod  = self.__Landscape[WarrenX][WarrenY].Warren.GetRabbitCount()
    for FoxX in range(0, self.__LandscapeSize):
      for FoxY in range (0, self.__LandscapeSize):
        if not self.__Landscape[FoxX][FoxY].Fox is None:
          Dist = self.__DistanceBetween(FoxX, FoxY, WarrenX, WarrenY)
          if Dist <= 3.5:
            PercentToEat = 20
          elif Dist <= 7:
            PercentToEat = 10
          else:
            PercentToEat = 0
          RabbitsToEat = int(round(float(PercentToEat * RabbitCountAtStartOfPeriod / 100)))
          FoodConsumed = self.__Landscape[WarrenX][WarrenY].Warren.EatRabbits(RabbitsToEat)
          self.__Landscape[FoxX][FoxY].Fox.GiveFood(FoodConsumed)
          if self.__ShowDetail:
            print("  ", FoodConsumed, " rabbits eaten by fox at (", FoxX, ",", FoxY, ").", sep = "")

  def __DistanceBetween(self, x1, y1, x2, y2):
    return math.sqrt((pow(x1 - x2, 2) + pow(y1 - y2, 2)))

  def __DrawLandscape(self):
    print()
    print("TIME PERIOD:", self.__TimePeriod)
    print()
    print("   ", end = "")
    for x in range (0, self.__LandscapeSize):
      if x < 10:
        print(" ", end = "")
      print(x, "|", end = "")
    print()
    for x in range (0, self.__LandscapeSize * 4 + 3):
      print("-", end = "")
    print()
    for y in range (0, self.__LandscapeSize):
      if y < 10:
        print(" ", end = "")
      print("", y, "|", sep = "", end = "")
      for x in range (0, self.__LandscapeSize):
        if not self.__Landscape[x][y].Warren is None:
          if self.__Landscape[x][y].Warren.GetRabbitCount() < 10:
            print(" ", end = "")
          print(self.__Landscape[x][y].Warren.GetRabbitCount(), end = "")
        else:
          print("  ", end = "")
        if not self.__Landscape[x][y].Fox is None:
          print("F", end = "")
        else:
          print(" ", end = "")
        print("|", end = "")
      print()

class Warren:
  def __init__(self, Variability, RabbitCount = 0):
    self.__MAX_RABBITS_IN_WARREN = 99
    self.__RabbitCount = RabbitCount
    self.__PeriodsRun = 0
    self.__AlreadySpread = False
    self.__Variability = Variability
    self.__Rabbits = []
    for Count in range(0, self.__MAX_RABBITS_IN_WARREN):
      self.__Rabbits.append(None)
    if self.__RabbitCount == 0:
      self.__RabbitCount = int(self.__CalculateRandomValue(int(self.__MAX_RABBITS_IN_WARREN / 4), self.__Variability))
    for r in range (0, self.__RabbitCount):
      self.__Rabbits[r] = Rabbit(self.__Variability)

  def __CalculateRandomValue(self, BaseValue, Variability):
    return BaseValue - (BaseValue * Variability / 100) + (BaseValue * random.randint(0, Variability * 2) / 100)

  def GetRabbitCount(self): 
    return self.__RabbitCount

  def NeedToCreateNewWarren(self): 
    if self.__RabbitCount == self.__MAX_RABBITS_IN_WARREN and not self.__AlreadySpread:
      self.__AlreadySpread = True
      return True
    else:
      return False

  def WarrenHasDiedOut(self):
    if self.__RabbitCount == 0:
      return True
    else:
      return False

  def AdvanceGeneration(self, ShowDetail):
    self.__PeriodsRun += 1
    if self.__RabbitCount > 0:
      self.__KillByOtherFactors(ShowDetail)
    if self.__RabbitCount > 0:
      self.__AgeRabbits(ShowDetail)
    if self.__RabbitCount > 0 and self.__RabbitCount <= self.__MAX_RABBITS_IN_WARREN:
      if self.__ContainsMales():
        self.__MateRabbits(ShowDetail)
    if self.__RabbitCount == 0 and ShowDetail:
      print("  All rabbits in warren are dead")

  def EatRabbits(self, RabbitsToEat):
    DeathCount = 0
    if RabbitsToEat > self.__RabbitCount:
      RabbitsToEat = self.__RabbitCount
    while DeathCount < RabbitsToEat:
      RabbitNumber = random.randint(0, self.__RabbitCount - 1)
      if not self.__Rabbits[RabbitNumber] is None:
        self.__Rabbits[RabbitNumber] = None
        DeathCount += 1
    self.__CompressRabbitList(DeathCount)
    return RabbitsToEat

  def __KillByOtherFactors(self, ShowDetail):
    DeathCount = 0
    for r in range (0, self.__RabbitCount):
      if self.__Rabbits[r].CheckIfKilledByOtherFactor():
        self.__Rabbits[r] = None
        DeathCount += 1
    self.__CompressRabbitList(DeathCount)
    if ShowDetail:
      print(" ", DeathCount, "rabbits killed by other factors.")

  def __AgeRabbits(self, ShowDetail):
    DeathCount = 0
    for r in range (0, self.__RabbitCount):
      self.__Rabbits[r].CalculateNewAge()
      if self.__Rabbits[r].CheckIfDead():
        self.__Rabbits[r] = None
        DeathCount += 1
    self.__CompressRabbitList(DeathCount)
    if ShowDetail:
      print(" ", DeathCount, "rabbits die of old age.")

  def __MateRabbits(self, ShowDetail):
    Mate = 0
    Babies = 0 
    for r in range (0, self.__RabbitCount):
      if self.__Rabbits[r].IsFemale() and self.__RabbitCount + Babies < self.__MAX_RABBITS_IN_WARREN:
        Mate = random.randint(0, self.__RabbitCount - 1)
        while Mate == r or self.__Rabbits[Mate].IsFemale():
          Mate = random.randint(0, self.__RabbitCount - 1)
        CombinedReproductionRate = (self.__Rabbits[r].GetReproductionRate() + self.__Rabbits[Mate].GetReproductionRate()) / 2
        if CombinedReproductionRate >= 1:
          self.__Rabbits[self.__RabbitCount + Babies] = Rabbit(self.__Variability, CombinedReproductionRate)
          Babies += 1
    self.__RabbitCount = self.__RabbitCount + Babies
    if ShowDetail:
      print(" ", Babies, "baby rabbits born.")

  def __CompressRabbitList(self, DeathCount):
    if DeathCount > 0:
      ShiftTo = 0
      ShiftFrom  = 0
      while ShiftTo < self.__RabbitCount - DeathCount:
        while self.__Rabbits[ShiftFrom] is None:
          ShiftFrom += 1
        if ShiftTo != ShiftFrom:
          self.__Rabbits[ShiftTo] = self.__Rabbits[ShiftFrom]
        ShiftTo += 1
        ShiftFrom += 1
      self.__RabbitCount = self.__RabbitCount - DeathCount

  def __ContainsMales(self):
    Males = False
    for r in range (0, self.__RabbitCount):
      if not self.__Rabbits[r].IsFemale():
        Males = True
    return Males

  def Inspect(self):
    print("Periods Run", self.__PeriodsRun, "Size", self.__RabbitCount)

  def ListRabbits(self):
    if self.__RabbitCount > 0:
      for r in range (0, self.__RabbitCount):
        self.__Rabbits[r].Inspect()

class GiantWarren(Warren):
  def __init__(self, Variability, RabbitCount = 1):
    super(GiantWarren, self).__init__(self.__RabbitCount, Variability)
    self.__MAX_RABBITS_IN_WARREN = 200
    self.__RabbitCount = RabbitCount
    self.__PeriodsRun = 0
    self.__Variability = Variability
    self.__Rabbits = []

    for Count in range(0, self.__MAX_RABBITS_IN_WARREN):
      self.__Rabbits.append(None)
    if self.__RabbitCount == 1:
      self.__RabbitCount = int(self.__CalculateRandomValue(int(self.__MAX_RABBITS_IN_WARREN / 4), self.__Variability))
    for r in range (0, self.__RabbitCount):
      self.__Rabbits[r] = Rabbit(self.__Variability)

class Animal:
  _ID = 1

  def __init__(self, AvgLifespan, AvgProbabilityOfDeathOtherCauses, Variability):
    self._NaturalLifespan = int(AvgLifespan * self._CalculateRandomValue(100, Variability) / 100)
    self._ProbabilityOfDeathOtherCauses = AvgProbabilityOfDeathOtherCauses * self._CalculateRandomValue(100, Variability) / 100
    self._IsAlive = True
    self._ID = Animal._ID
    self._Age = 0
    Animal._ID += 1

  def CalculateNewAge(self):
    self._Age += 1
    if self._Age >= self._NaturalLifespan:
      self._IsAlive = False

  def CheckIfDead(self): 
    return not self._IsAlive

  def Inspect(self):
    print("  ID", self._ID, "", end = "")
    print("Age", self._Age, "", end = "")
    print("LS", self._NaturalLifespan, "", end = "")
    print("Pr dth", round(self._ProbabilityOfDeathOtherCauses, 2), "", end = "")

  def CheckIfKilledByOtherFactor(self):
    if random.randint(0, 100) < self._ProbabilityOfDeathOtherCauses * 100:
      self._IsAlive = False
      return True
    else:
      return False

  def _CalculateRandomValue(self, BaseValue, Variability):
    return BaseValue - (BaseValue * Variability / 100) + (BaseValue * random.randint(0, Variability * 2) / 100)

class Fox(Animal):
  def __init__(self, Variability, genderRatio = 33):
    self.__DEFAULT_LIFE_SPAN = 7
    self.__DEFAULT_PROBABILITY_DEATH_OTHER_CAUSES = 0.1
    super(Fox, self).__init__(self.__DEFAULT_LIFE_SPAN, self.__DEFAULT_PROBABILITY_DEATH_OTHER_CAUSES, Variability)
    self.__FoodUnitsNeeded = int(10 * self._CalculateRandomValue(100, Variability) / 100)
    self.__FoodUnitsConsumedThisPeriod  = 0
    if random.randint(0, 100) < genderRatio:
      self.__Gender = Genders.Male
    else:
      self.__Gender = Genders.Female


  def AdvanceGeneration(self, ShowDetail):
    if self.__FoodUnitsConsumedThisPeriod == 0:
      self._IsAlive = False
      if ShowDetail:
        print("  Fox dies as has eaten no food this period.")
    else:
      if self.CheckIfKilledByOtherFactor():
        self._IsAlive = False
        if ShowDetail:
          print("  Fox killed by other factor.")
      else:
        if self.__FoodUnitsConsumedThisPeriod < self.__FoodUnitsNeeded:
          self.CalculateNewAge()
          if ShowDetail:
            print("  Fox ages further due to lack of food.")
        self.CalculateNewAge()
        if not self._IsAlive:
          if ShowDetail:
            print("  Fox has died of old age.")

  def ResetFoodConsumed(self):
    self.__FoodUnitsConsumedThisPeriod = 0

  def ReproduceThisPeriod(self): 
    REPRODUCTION_PROBABILITY  = 0.25
    if self.__Gender == Genders.Female:
      if random.randint(0, 100) < REPRODUCTION_PROBABILITY * 100:
        return True
      else:
        return False

  def GiveFood(self, FoodUnits):
    self.__FoodUnitsConsumedThisPeriod = self.__FoodUnitsConsumedThisPeriod + FoodUnits

  def IsFemale(self):
    if self.__Gender == Genders.Female:
      return True
    else:
      return False

  def Inspect(self):
    super(Fox, self).Inspect()
    print("Food needed", self.__FoodUnitsNeeded, "", end = "")
    print("Food eaten", self.__FoodUnitsConsumedThisPeriod, "", end = "")
    if self.__Gender == Genders.Male:
      gender = "Male"
    else:
      gender = "Female"
    print("Gender", gender, "", end="")
    print()

class Genders(enum.Enum):
  Male = 1
  Female = 2

class Rabbit(Animal):
  def __init__(self, Variability, ParentsReproductionRate = 1.2, genderRatio=50):
    self.__DEFAULT_LIFE_SPAN = 4
    self.__DEFAULT_PROBABILITY_DEATH_OTHER_CAUSES  = 0.05
    super(Rabbit, self).__init__(self.__DEFAULT_LIFE_SPAN, self.__DEFAULT_PROBABILITY_DEATH_OTHER_CAUSES, Variability)
    self.__ReproductionRate = ParentsReproductionRate * self._CalculateRandomValue(100, Variability) / 100
    if random.randint(0, 100) < genderRatio:
      self.__Gender = Genders.Male
    else:
      self.__Gender = Genders.Female

  def Inspect(self):
    super(Rabbit, self).Inspect()
    print("Rep rate", round(self.__ReproductionRate, 1), "", end = "")
    if self.__Gender == Genders.Female:
      print("Gender Female")
    else:
      print("Gender Male")

  def IsFemale(self):
    if self.__Gender == Genders.Female:
      return True
    else:
      return False

  def GetReproductionRate(self): 
    return self.__ReproductionRate

def Main():
  MenuOption = 0
  while MenuOption != 3:
    print("Predator Prey Simulation Main Menu")
    print()
    print("1. Run simulation with default settings")
    print("2. Run simulation with custom settings")
    print("3. Rabbit Paradise")
    print("4. Exit")
    print()
    try:
      MenuOption = int(input("Select option: "))
    except:
      print("What you have entered is not an integer. Try again")
    if MenuOption == 1 or MenuOption == 2 or MenuOption == 3:
      if MenuOption == 1:
        LandscapeSize = 15
        InitialWarrenCount = 5
        InitialFoxCount = 5
        Variability = 0
        FixedInitialLocations = True
      elif MenuOption == 3:
        LandscapeSize = 20
        InitialWarrenCount = 20
        InitialFoxCount = 0
        Variability = 1
        FixedInitialLocations = False
      else:
        LandscapeSize = int(input("Landscape Size: "))
        InitialWarrenCount = int(input("Initial number of warrens: "))
        InitialFoxCount = int(input("Initial number of foxes: "))
        Variability = int(input("Randomness variability (percent): "))
        FixedInitialLocations = False
      Sim = Simulation(LandscapeSize, InitialWarrenCount, InitialFoxCount, Variability, FixedInitialLocations)
  input()

if __name__ == "__main__":
  Main()

Answer 1

问题是在方法名和属性名上不加区分地使用双下划线前缀。它用于调用名称混乱，并专门用于防止继承；它提供了最接近Python的“私有”变量。在

学生肯定不想在这里的任何地方使用它；一般来说，我建议永远不要使用它。给所有的东西起个普通的名字。在

（另外请注意，由于他们是在编程Python，所以应该使用Python惯例来命名：变量、属性和方法应该有lower_case_with_underscore名称，而不是CamelCase，它是用于类名的。）