4.2 代理迭代:

你构建了一个自定义容器对象,里面包含了列表,元组或其他可迭代对象。

class Node:
def __init__(self, value):
self._value = value
self._children = []
# Example
if __name__ == '__main__':
root = Node(0)
print root
print type(root)


C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/Django/a36.py
<__main__.Node instance at 0x01D9BDF0>
<type 'instance'>


将实例转换成字符串:

class Node:
def __init__(self, value):
self._value = value
self._children = []

def __repr__(self):
return 'Node({!r})'.format(self._value)
# Example
if __name__ == '__main__':
root = Node(0)
print root
print type(root)

C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/Django/a36.py
Node(0)
<type 'instance'>

Process finished with exit code 0


class Node:
def __init__(self, value):
self._value = value
self._children = []

# def __repr__(self):
# return 'Node({!r})'.format(self._value)

def add_child(self, node):
self._children.append(node)
# Example
if __name__ == '__main__':
root = Node(0)
print root
print type(root)
child1 = Node(1)
child2 = Node(2)
print '--------------'
print child1
print child2
root.add_child(child1)
root.add_child(child2)
print root._children
print '1111111111111'
for x in root._children:
print x


C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/Django/a36.py
<__main__.Node instance at 0x024DF940>
<type 'instance'>
--------------
<__main__.Node instance at 0x024CF0D0>
<__main__.Node instance at 0x02513DF0>
[<__main__.Node instance at 0x024CF0D0>, <__main__.Node instance at 0x02513DF0>]
1111111111111
<__main__.Node instance at 0x024CF0D0>
<__main__.Node instance at 0x02513DF0>

Process finished with exit code 0


class Node:
def __init__(self, value):
self._value = value
self._children = []

# def __repr__(self):
# return 'Node({!r})'.format(self._value)

def add_child(self, node):
self._children.append(node)

def __iter__(self):
return iter(self._children)
# Example
if __name__ == '__main__':
root = Node(0)
print root
print type(root)
child1 = Node(1)
child2 = Node(2)
print '--------------'
print child1
print child2
root.add_child(child1)
root.add_child(child2)
print root._children
print '1111111111111'
for x in root:
print x

C:\Python27\python.exe C:/Users/TLCB/PycharmProjects/untitled/mycompany/Django/a36.py
<__main__.Node instance at 0x02733DF0>
<type 'instance'>
--------------
<__main__.Node instance at 0x0273C3A0>
<__main__.Node instance at 0x0273C3C8>
[<__main__.Node instance at 0x0273C3A0>, <__main__.Node instance at 0x0273C3C8>]
1111111111111
<__main__.Node instance at 0x0273C3A0>
<__main__.Node instance at 0x0273C3C8>