How do I reverse the direction of arrows in my python anytree graphviz output?

I am building trees that are designed to represent a flow from leaves to the root of the tree using the anytree package in python. I have the following code.

from anytree import Node
from anytree.exporter import DotExporter
A = Node('A')
B = Node('B', parent = A)
C = Node('C', parent = A)
DotExporter(A).to_picture('example.png')

And it produces the following image.

I want to modify this image such that the arrows point in the opposite direction. I know that in graphviz adding [dir=back] to an edge definition line will give me the result that I want. By running the following code:

for line in DotExporter(A):
    print(line)

I get the output:

digraph tree {
    "A";
    "B";
    "C";
    "A" -> "B";
    "A" -> "C";
}

But how do I modify the output of DotExporter from the anytree interface to add [dir=back] to the edge definition lines and reverse the direction of the arrows?

To modify the edge attributes defined for Dot by the DotExporter you need to change the edgeattrfunc attribute of DotExporter as such.

from anytree import Node
from anytree.exporter import DotExporter
A = Node('A')
B = Node('B', parent = A)
C = Node('C', parent = A)
DotExporter(A, edgeattrfunc = lambda node, child: "dir=back").to_picture('example.png')

Looking at the output, you now get:

for line in DotExporter(A, edgeattrfunc = lambda node, child: "dir=back"):
    print(line)

digraph tree {
    "A";
    "B";
    "C";
    "A" -> "B" [dir=back];
    "A" -> "C" [dir=back];
}

Which produces the following image.