从python的rpg Traveller系统生成行星

Question

我一直在努力教自己如何使用面向对象的代码，我认为一种有趣的学习方法是编写一组行星，基于Mongoose的规则系统。

当一个行星物体被创建时，它会算法地生成一个行星。我定义了一个string方法和一个json方法来返回行星数据。函数two_dice()模拟两个骰子的和。

from models.common import two_dice
from random import randint

# Translate int values to string equivalent
numMap = {0: '0', 1: '1', 2: '2', 3: '3', 4: '4', 5: '5', 6: '6', 7: '7', 8: '8', 9: '9', 10: 'A', 11: 'B', 12: 'C',
          13: 'D', 14: 'E', 15: 'F', '-': '-'}


class Planet(object):
    def __init__(self, name, **kwargs):
        """
        creates a planet object with algorithmically defined attributes
        Attributes can be passed as keywords and creation process will account for them
        """
        self.name = name
        # Size is 2D - 2
        self.size = self._check_kwargs("size", 10, 0, kwargs)
        if self.size is None:
            self.size = two_dice()-2
        # Atmosphere is Size + 2D - 7. If size = 0, atmosphere = 0
        self.atmosphere = self._check_kwargs('atmosphere', 15, 0, kwargs)
        if self.atmosphere is None:
            self.atmosphere = self.size+two_dice()-7
            if self.size == 0:
                self.atmosphere = 0
            self.atmosphere = max(0, self.atmosphere)
        # Temperature is 2D. Affected by atmosphere type
        self.temperature = self._check_kwargs('temperature', 12, 0, kwargs)
        if self.temperature is None:
            self.temperature = two_dice()
            if self.atmosphere in [2, 3]:
                self.temperature -= 2
            elif self.atmosphere in [4, 5, 14]:
                self.temperature -= 2
            elif self.atmosphere in [8, 9]:
                self.temperature += 1
            elif self.atmosphere in [10, 13, 15]:
                self.temperature += 2
            elif self.atmosphere in [11, 12]:
                self.temperature += 6
            self.temperature = max(0, self.temperature)
            self.temperature = min(12, self.temperature)
        # Hydrographics is atmosphere + 2D - 7. Affected by size, temperature and atmosphere
        self.hydrographics = self._check_kwargs('hydrographics', 10, 0, kwargs)
        if self.hydrographics is None:
            if self.size <= 1:
                self.hydrographics = 0
            else:
                self.hydrographics = self.atmosphere + two_dice() - 7
                if self.atmosphere in [0, 1, 10, 11, 12]:
                    self.hydrographics -= 4
                if self.atmosphere != 13:
                    if self.temperature in [10, 11]:
                        self.hydrographics -= 2
                    elif self.temperature >= 12:
                        self.hydrographics -= 6
            self.hydrographics = max(0, self.hydrographics)
            self.hydrographics = min(10, self.hydrographics)
        # Population is 2D - 2.
        self.population = self._check_kwargs('population', 12, 0, kwargs)
        if self.population is None:
            self.population = two_dice() - 2
        # Government is population + 2D - 7.
        self.government = self._check_kwargs('government', 15, 0, kwargs)
        if self.government is None:
            self.government = self.population + two_dice() - 7
            if self.population == 0:
                self.government = 0
            self.government = max(0, self.government)
            self.government = min(15, self.government)
        # Culture is determined by rolling two dice, and concatenating the result.
        self.culture = randint(1, 6) + randint(1, 6) * 10
        if self.population == 0:
            self.culture = 0
        # Law level is government + 2D - 7
        self.law_level = self._check_kwargs('law_level', 9, 0, kwargs)
        if self.law_level is None:
            self.law_level = self.government + two_dice() - 7
            if self.population == 0:
                self.law_level = 0
            self.law_level = max(0, self.law_level)
            self.law_level = min(9, self.law_level)
        # Starport level is 2D, affected by population
        self.starport = self._check_kwargs('starport', 12, 0, kwargs)
        if self.starport is None:
            self.starport = two_dice()
            if self.population >= 10:
                self.starport += 2
            elif self.population >= 8:
                self.starport += 1
            elif self.population <= 2:
                self.starport -= 2
            elif self.population <= 4:
                self.starport -= 1
            self.starport = min(12, self.starport)
            self.starport = max(0, self.starport)
        # tech level is 1D, affected by lots of modifiers
        self.tech_level = self._check_kwargs('tech_level', 15, 0, kwargs)
        if self.tech_level is None:
            self.tech_level = randint(1, 6)
            if self.atmosphere <= 3 or self.atmosphere >= 10:
                self.tech_level += 1
            if self.size in [0, 1]:
                self.tech_level += 2
            elif self.size in [2, 3, 4]:
                self.tech_level += 1
            if self.hydrographics in [0, 9]:
                self.tech_level += 1
            elif self.hydrographics == 10:
                self.tech_level += 2
            if self.population in [1, 2, 3, 4, 5, 8]:
                self.tech_level += 1
            elif self.population == 9:
                self.tech_level += 2
            elif self.population == 10:
                self.tech_level += 4
            if self.government in [0, 5]:
                self.tech_level += 1
            elif self.government in [13, 14]:
                self.tech_level -= 2
            elif self.government == 7:
                self.tech_level += 2
            if self.starport >= 11:
                self.tech_level += 6
            elif self.starport >= 9:
                self.tech_level += 4
            elif self.starport >= 7:
                self.tech_level += 2
            elif self.starport <= 2:
                self.tech_level -= 4
            if self.population == 0:
                self.tech_level = 0
            self.tech_level = max(0, self.tech_level)
            self.tech_level = min(15, self.tech_level)

    @staticmethod
    def _check_kwargs(keyword, maxvalue, minvalue, kwargs):
        """
        Checks the given keyword exists, and is between given max & min values
        Returns keyword value if exists, otherwise None
        """
        if keyword in kwargs:
            if maxvalue >= kwargs[keyword] >= minvalue:
                return kwargs[keyword]
            else:
                raise ValueError("{} must be between {} and {}".format(keyword, maxvalue, minvalue))
        else:
            return None

    def json(self):
        return {'name': self.name,
                'size': self.size,
                'atmosphere': self.atmosphere,
                'temperature': self.temperature,
                'hydrographics': self.hydrographics,
                'population': self.population,
                'government': self.government,
                'culture': self.culture,
                'law_level': self.law_level,
                'starport': self.starport,
                'tech_level': self.tech_level}

    def __str__(self):
        attributes_list = [self.size, self.atmosphere, self.hydrographics, self.population, self.government,
                           self.law_level, '-', self.tech_level]
        if self.starport <= 2:
            starport = 'X'
        elif self.starport <= 4:
            starport = 'E'
        elif self.starport <= 6:
            starport = 'D'
        elif self.starport <= 8:
            starport = 'C'
        elif self.starport <= 10:
            starport = 'B'
        else:
            starport = 'A'
        return self.name + ' ' + starport + ''.join(list(map(lambda X: numMap[X],attributes_list)))

这是我第一次尝试写一门课。虽然它目前是独立的，但我希望它能够适应一个更大的项目。有什么方法可以改进这一点，使它更好地遵循最佳实践，并删除重复的代码？

Answer 1

1. 似乎没有将culture作为关键字参数传递的方法。这看起来像是个疏忽。
2. 没有检查无效的关键字参数。这意味着，如果我们做了一个排版错误，我们不会发现它，但结果将是错误的：>>>行星=行星(‘Hrod’，atmopshere=10) >>> planet.atmosphere 7最好是这样的异常: TypeError：'atmopshere‘是这个函数的无效关键字参数。
3. 函数two_dice似乎有些奇怪的具体。Traveller使用了很多2d6卷，但是在代码中我可以看到像randint(1, 6)和two_dice() - 7这样的表达式。我认为这样的东西会有帮助:导入roll (骰子)：“”滚骰子并返回它们的和。参数必须是一个描述滚动的字符串，例如'2d6+3‘来滚动两个6边的骰子并添加三个。“match = re.match(r'(\d*)d(\d*)(\d+)?$'，如果不匹配的话)：举起ValueError(f“预期的骰子，但得到{ dice !r}") n，边，红利= match.groups()边=int(边)返回和_ in范围(int(N))+int(红利或0)，这样读者可能会更清楚地写出roll('1d6')或roll('2d6-7')，并且更容易对照规则簿进行检查。
4. 对于两组不同的大气值，温度由相同的值(−2)调节:如果self.atmosphere in : self.temperature -= 2 elif self.atmosphere in : self.temperature -= 2是self.temperature -= 1的最后一行吗？
5. numMap将整数从0映射到15，映射为它们的十六进制等价物，并将连字符映射到它自己。如果不是因为连字符，您可以编写format(n, 'X')而不需要numMap。从numMap的使用来看，连字符的重点似乎是在__str__方法中实现一个特殊情况。但正如它在Python的禅宗中所说的那样，特例不足以打破规则。因此，我建议让__str__变得更复杂一些，以消除特例，这将允许您使用format(..., 'X')，而这又将允许您摆脱numMap。
6. 有很多重复。对于每个属性，我们都有一个名称，我们有一个最大值，我们可能需要在字符串代码中包含它的十六进制数字。我们可以将这些数据放入一个表中，比如：_ATTRIBUTES =，我们可以将生成每个属性的规则放入它们自己的方法中，类似于这样: def _size_default(self)：回滚(‘2D6-2’) def _atmosphere_default(self)：如果self.size == 0:返回0:返回self.size + roll('2d6-7') _TEMPERATURE_ADJUST = def _temperature_default(self)：回滚(‘2D6’)+ self._TEMPERATURE_ADJUST def _hydrographics_default(self)：如果self.size <= 1：返回0水文= self.atmosphere + roll('2d6-7')，如果self.atmosphere在(0，1，10，11，12)：水文-= 4如果self.atmosphere != 13: if self.temperature in (10，( 11)：水文学-= 2 elif self.temperature >= 12:水文资料-= 6返回水文资料(自)：返回卷(‘2D6-2’) def _government_default(self)：如果self.population == 0:返回0其他:返回self.population + roll('2d6-7') def _culture_default(自我)：if self.population== 0:返回0 return :返回滚(‘1d6’)* 10 +滚(‘1d6’) def _law_level_default(self)：如果self.population == 0:返回0:返回self.government + roll('2d6-7') _STARPORT_ADJUST = def _starport_default(self)：回滚(‘2D6’)+ self._STARPORT_ADJUST _TECH_LEVEL__tech_level_default(self)：如果self.population == 0:返回0 tech_level = roll('1d6')属性，Self._TECH_LEVEL_ADJUST中的调整: tech_level += adjustment.get(getattr(self，attribute)，0)返回tech_level，现在我们可以系统地处理关键字参数，比如上面的不动点§1和§2，并且避免重复:对于属性，最大值，_ in self._ATTRIBUTES: if属性in kwargs: value =kwargs.pop(属性)如果不是(0 <=值<=最大值)：引发ValueError(f"{ attribute !r}必须介于0和“{max}包含”)否则: value = getattr(self，'_‘+ attribute + '_default')()值= max(0，min(值)，)如果kwargs: kwarg =next(TypeError(Kwargs))引发_check_kwargs (f“{kwarg！r}是”这个函数“的一个无效关键字参数)，那么我们就不再需要D28了，json和__str__方法变成: def json(self)：D30= dict(name=self.name) for attribute，_，_ in self._ATTRIBUTES：_STARPORT_CODE = getattr(self，attribute )返回结果_STARPORT_CODE= 'XXXEEDDCCBBAAAAA‘def __str__(self)：返回"{} -{}“.format( self.name，self._STARPORT_CODE，’.联接)(格式(getattr(self，attribute)，'X')用于属性，_，self._ATTRIBUTES中的代码，如果是代码)，格式(self.tech_level，‘X’)