#
# A class that provides an iterator generator method.
#
class Node:
    def __init__(self, name='<noname>', value='<novalue>', children=None):
        self.name = name
        self.value = value
        self.children = children
        if children is None:
            self.children = []
        else:
            self.children = children
    def set_name(self, name): self.name = name
    def get_name(self): return self.name
    def set_value(self, value): self.value = value
    def get_value(self): return self.value
    def iterchildren(self):
        for child in self.children:
            yield child
    #
    # Print information on this node and walk over all children and
    #   grandchildren ...
    def walk(self, level=0):
        print '%sname: %s  value: %s' % (
            get_filler(level), self.get_name(), self.get_value(), )
        for child in self.iterchildren():
            child.walk(level + 1)


#
# An function that is the equivalent of the walk() method in
#   class Node.
#
def walk(node, level=0):
    print '%sname: %s  value: %s' % (
        get_filler(level), node.get_name(), node.get_value(), )
    for child in node.iterchildren():
        walk(child, level + 1)

def get_filler(level):
    return '    ' * level

def test():
    a7 = Node('gilbert', '777')
    a6 = Node('fred', '666')
    a5 = Node('ellie', '555')
    a4 = Node('daniel', '444')
    a3 = Node('carl', '333', [a4, a5])
    a2 = Node('bill', '222', [a6, a7])
    a1 = Node('alice', '111', [a2, a3])
    # Use the walk method to walk the entire tree.
    print 'Using the method:'
    a1.walk()
    print '=' * 30
    # Use the walk function to walk the entire tree.
    print 'Using the function:'
    walk(a1)

test()