如何在 Python 中过滤 ttk.treeview？

Question

I have a python tkinter application that contains a ttk.treeview widget.

The widget displays a list of files found on a specific directory tree with a specific extension - this was trivial to build with tt.treeview widget.

There is a request to enable "on-the-fly" filtering of the tree - eg, the user types in an Entry some string, and as he/she types, the tree removes elements that don't match the typed string so far.

I was exploring the Treeview documentation, tried the detach and reattach methods but with no luck.

detach indeed removes the non-matched elements from the tree, but if the user hit Backspace , I can no longer iterate correctly on the tree to restore those detached elements as get_children method will not return them.

def filter_tree(self):
    search_by = self.search_entry.get()
    self.tree_detach_leaf_by_regex(self.current_loaded_folder, search_by, "")

def tree_detach_leaf_by_regex(self, root, regex, parent):
    if self.treeview.get_children(root):
        for child in self.treeview.get_children(root):
            self.tree_detach_leaf_by_regex(child, regex, root)
    else:
        if not re.match(regex, self.treeview.item(root)["text"]):
            self.elements_index_within_parent[root] = self.treeview.index(root)
            self.elements_parents[parent] = 1
            self.treeview.detach(root)
        else:
            self.treeview.reattach(root, parent, self.elements_index_within_parent[root])

Looking forward to read your advice.

Answer 1

To make my answer reusable by anybody, I have to tell more than directly answering your question. If you directly want to see how I do to get detached items (thus without using the method get_children which cannot get detached items' id), jump to the definition of the method whose name is _columns_searcher .

---

Introduction

Let's first define some attributes.

 @property def _to_search(self): key = 'to_search' if key not in self._cache: self._cache[key] = tk.StringVar() return self._cache[key] def _set_search_entry(self): ent = ttk.Entry( self.root, # or canvas, or frame ... #... textvariable=self._to_search ) ent.grid( #... ) ent.bind( '<Return>', self._columns_searcher ) return ent @property def search_entry(self): key = 'search_entry' if key not in self._cache: self._cache[key] = self._set_search_entry() return self._cache[key]

---

Core answer

What follows is the part which directly show how to re-attach user-detached items. First note that, as the OP mentions, get_children only return ids of attached items. Second note that the only thing you need to re-attach detached items is their id. Which implies thus to trace/save them when they are detached so as to be able to re-attach them.

def _brut_searcher(self, children, query):
    i_r = -1
    for item_id in children:
        text = self.tree.item(item_id)['text'] # already contains the strin-concatenation (over columns) of the row's values
        if query in text:
            i_r += 1
            self.tree.reattach(item_id, '', i_r)
        else:
            self._detached.add(item_id)
            self.tree.detach(item_id)

Note that children above contains all items , be them detached.

 def _brut_searcher(self, children, query): i_r = -1 for item_id in children: text = self.tree.item(item_id)['text'] # already contains the strin-concatenation (over columns) of the row's values if query in text: i_r += 1 self.tree.reattach(item_id, '', i_r) else: self._detached.add(item_id) self.tree.detach(item_id)

Answer 2

From what I see, detach is almost same as delete. row is gone and you have no access to it. You have to make a copy of "detached" items, just id, name or more, if you have advance treeview structure, and then go over elements in both lists and sort it out. Difference is that if you detach item and check it's id with "exists" function, it should return true