Question

我正在学习如何通过设计家谱来制作列表。下面是我提出的一种方法，但我在打印结果时遇到问题。例如：

如果A有2个孩子，B＆amp; C... 然后B有2个孩子，D＆amp; E. .. 而C只有孩子，F ...

我希望打印结果：[A，[B，[D，E]]，[C，[F]]]

感谢我的代码中的任何改进，如何打印上述结果的建议，或以图形形式打印。

class FamilyTree:
    def __init__(self, root):
        self.name = [root]
        nmbr = int(input("How many children does " + root + " have?"))
        if nmbr is not 0:
            for i, child in enumerate(range(nmbr)):
                name = input("What is one of " + root + "'s child's name?")
                setattr(self, "child{0}".format(i), FamilyTree(name))
r = print(FamilyTree('A'))

Answer 1

您可以使用print()函数调用的__str__方法：

class FamilyTree:
    def __init__(self, root):
        self.name = root
        self.children = []
        nmbr = int(input("How many children does " + root + " have? "))
        if nmbr is not 0:
            for i, child in enumerate(range(nmbr)):
                name = input("What is one of " + root + "'s child's name? ")
                self.children.append(FamilyTree(name))
    def __str__(self):
        return '[' + self.name + ''.join(', ' + str(c) for c in self.children) + ']'
r = print(FamilyTree('A'))

Answer 2

将对象创建与输入和输出分开是个好主意。此外，使用setattr会使编写输出变得更加困难。

这是一个解决方案，允许您创建一个FamilyTree，无论是否有来自用户的阅读输入：

class FamilyTree:
    def __init__(self, root, childs = []):
        self.name = root
        self.childs = childs

    def read(self):
        nmbr = int(input("How many children does " + self.name + " have? "))
        if nmbr is not 0:
            for _ in range(nmbr):
                name = input("What is one of " + self.name + "'s child's name? ")
                child = FamilyTree(name)
                child.read()
                self.childs.append(child)

    def __repr__(self):
        if len(self.childs) == 0:
            return str("{}".format(self.name))
        else:
            return str("{}, {}".format(self.name, self.childs))

# creates a FamilyTree directly so we can test the output
r = FamilyTree(
        'A',
        [
            FamilyTree(
                'B',
                [FamilyTree('C'), FamilyTree('C')]
            ),
            FamilyTree(
                'C',
                [FamilyTree('F')]
            )
        ]
    )

# or read input from the user
# r = FamilyTree('A')
# r.read()

print(r)

输出

A, [B, [C, C], C, [F]]

打印列表列表

2 个答案: