I have wxFrame with a bunch of controls (splitter window, tool bar,
panes, trees, list controls...) and I want to traverse the entire
object tree looking for all the controls that are wxTreeControls. I
apparently do not understand how the generators/iterators work with
recursion, and would like some help.
and I call it thusly:
t = traverse( frame )
for n in t:
print "node = ", n
but it only results in the top two objects being returned -- the top
level descendants of the frame.
However, if I remove the yield statement, I get full tree
traversal...Obviously, I'm missing something -- anyone clear this up
for me? All help appreciated.
You are recursively calling traverse as if it was a function, but it isn't. It's a generator. Something like this may do it:
def traverse(node):
for child in node.GetChildren():
yield child
for grandchild in traverse(child):
yield grandchild
Although simply building a list and returning it would be simpler from a conceptual viewpoint, and since all the nodes are already present, will likely always be a fairly small collection, and nothing needs to be "generated" then there is no real performance hit either:
def traverse(node):
L = [node]
for child in node.GetChildren():
L += traverse(child)
return L
···
On 2/22/10 5:15 PM, billy pilgrim wrote:
Hi all,
I have wxFrame with a bunch of controls (splitter window, tool bar,
panes, trees, list controls...) and I want to traverse the entire
object tree looking for all the controls that are wxTreeControls. I
apparently do not understand how the generators/iterators work with
recursion, and would like some help.
but it only results in the top two objects being returned -- the top
level descendants of the frame.
However, if I remove the yield statement, I get full tree
traversal...Obviously, I'm missing something -- anyone clear this up
for me? All help appreciated.
Robin's solution (building a list) works quite well.
FWIW: there is no GetClassInfo support (that I could find), but
node.ClassName == 'wxPyTreeCtrl' found all my tree controls. Now, on
to the next windmill.
Cody: I tried your suggestion but I couldn't make it work, so I took
Robin's.
Thanks everyone, for your help, and for supporting wxPython.
Hopefully, I will eventually be able to help someone else.
:bp:
···
On Feb 22, 9:25 pm, Robin Dunn <ro...@alldunn.com> wrote:
On 2/22/10 5:15 PM, billy pilgrim wrote:
> Hi all,
> I have wxFrame with a bunch of controls (splitter window, tool bar,
> panes, trees, list controls...) and I want to traverse the entire
> object tree looking for all the controls that are wxTreeControls. I
> apparently do not understand how the generators/iterators work with
> recursion, and would like some help.
> I have a generator traverse:
> def traverse( node ):
> print "+traverse"
> kids = node.GetChildren()
> for kid in kids:
> traverse( kid )
> print "yield kid = ", kid
> yield kid
> but it only results in the top two objects being returned -- the top
> level descendants of the frame.
> However, if I remove the yield statement, I get full tree
> traversal...Obviously, I'm missing something -- anyone clear this up
> for me? All help appreciated.
You are recursively calling traverse as if it was a function, but it
isn't. It's a generator. Something like this may do it:
def traverse(node):
for child in node.GetChildren():
yield child
for grandchild in traverse(child):
yield grandchild
Although simply building a list and returning it would be simpler from a
conceptual viewpoint, and since all the nodes are already present, will
likely always be a fairly small collection, and nothing needs to be
"generated" then there is no real performance hit either:
def traverse(node):
L = [node]
for child in node.GetChildren():
L += traverse(child)
return L
--
Robin Dunn
Software Craftsmanhttp://wxPython.org