diff --git a/pysollib/tk/tktree.py b/pysollib/tk/tktree.py
index 34388def..2f34d0f2 100644
--- a/pysollib/tk/tktree.py
+++ b/pysollib/tk/tktree.py
@@ -63,10 +63,12 @@ class MfxTreeBaseNode:
     def draw(self, x, y, lastx=None, lasty=None):
         canvas, style = self.tree.canvas, self.tree.style
         topleftx = x + style.distx
-        toplefty = y - style.height / 2 #+++
+        toplefty = y - style.height / 2  # +++
         # draw the horizontal line
         if lastx is not None:
-            canvas.create_line(x, y, topleftx, y, stipple=style.linestyle, fill=style.linecolor)
+            canvas.create_line(
+                x, y, topleftx, y, stipple=style.linestyle,
+                fill=style.linecolor)
         # draw myself - ugly, ugly...
         self.selected = 0
         self.symbol_id = -1
@@ -93,7 +95,7 @@ class MfxTreeBaseNode:
             # note: I don't use Label + canvas.create_window here
             #   because it doesn't propagate events to the canvas
             #   and has some other re-display annoyances
-            ##print 'style.font:', style.font
+            # print 'style.font:', style.font
             self.text_id = canvas.create_text(x+1, y, text=self.text,
                                               anchor="w", justify="left",
                                               font=style.font,
@@ -108,8 +110,9 @@ class MfxTreeBaseNode:
                 pass
         elif self.selected:
             b = canvas.bbox(self.text_id)
-            self.textrect_id = canvas.create_rectangle(b[0]-1, b[1]-1, b[2]+1, b[3]+1,
-                                                       fill=bg, outline="")
+            self.textrect_id = canvas.create_rectangle(
+                b[0]-1, b[1]-1, b[2]+1, b[3]+1,
+                fill=bg, outline="")
             canvas.tag_lower(self.textrect_id, self.text_id)
             self.tree.nodes[self.textrect_id] = self
 
@@ -179,7 +182,6 @@ class MfxTreeNode(MfxTreeBaseNode):
                                          fill=style.linecolor)
         return ny
 
-
     def draw(self, x, y, ilastx=None, ilasty=None):
         # draw myself
         lx, ly, nx, ny = MfxTreeBaseNode.draw(self, x, y, ilastx, ilasty)
@@ -188,7 +190,7 @@ class MfxTreeNode(MfxTreeBaseNode):
             childx = nx + style.distx + style.width / 2
             childy = ny
             clastx = nx + style.distx + style.width / 2
-            clasty = ly + style.height /2
+            clasty = ly + style.height / 2
             ny = self.drawChildren(childx, childy, clastx, clasty)
         return lx, ly, x, ny
 
@@ -239,13 +241,14 @@ class MfxTreeInCanvas(MfxScrolledCanvas):
         self.keys = {}
         #
         self.style = self.Style()
-        ##self.style.text_normal_fg = self.canvas.cget("insertbackground")
-        self.style.text_normal_fg = self.canvas.option_get('foreground', '') or self.canvas.cget("insertbackground")
+        # self.style.text_normal_fg = self.canvas.cget("insertbackground")
+        self.style.text_normal_fg = self.canvas.option_get('foreground', '') \
+            or self.canvas.cget("insertbackground")
         self.style.text_normal_bg = bg
         #
         bind(self.canvas, "<ButtonPress-1>", self.singleClick)
         bind(self.canvas, "<Double-Button-1>", self.doubleClick)
-        ##bind(self.canvas, "<ButtonRelease-1>", xxx)
+        # bind(self.canvas, "<ButtonRelease-1>", xxx)
         self.pack(fill='both', expand=True)
 
     def destroy(self):
@@ -281,8 +284,8 @@ class MfxTreeInCanvas(MfxScrolledCanvas):
                 raise
         # set scroll region
         bbox = self.canvas.bbox("all")
-        ##self.canvas.config(scrollregion=bbox)
-        self.canvas.config(scrollregion=(0,0,bbox[2],bbox[3]))
+        # self.canvas.config(scrollregion=bbox)
+        self.canvas.config(scrollregion=(0, 0, bbox[2], bbox[3]))
         self.canvas.config(yscrollincrement=self.style.disty)
 
     def clear(self):
@@ -372,7 +375,7 @@ class DirectoryBrowser(MfxTreeInCanvas):
             return node.subnodes
         #
         dir = node.key
-        print "Getting %s" % dir
+        print("Getting %s" % dir)
         try:
             filenames = os.listdir(dir)
             filenames.sort()
@@ -381,14 +384,14 @@ class DirectoryBrowser(MfxTreeInCanvas):
         contents = []
         for filename in filenames:
             self.addNode(contents, node, os.path.join(dir, filename), filename)
-        ##print "gotten"
+        # print "gotten"
         return contents
 
     def singleClick(self, event=None):
         node = self.findNode(event)
         if not node:
             return
-        print "Clicked node %s %s" % (node.text, node.key)
+        print("Clicked node %s %s" % (node.text, node.key))
         if isinstance(node, MfxTreeLeaf):
             self.updateSelection(key=node.key)
         elif isinstance(node, MfxTreeNode):
@@ -404,5 +407,3 @@ if __name__ == "__main__":
     else:
         app = DirectoryBrowser(tk, ("/", "/home"))
     tk.mainloop()
-
-
diff --git a/tests/style/py-flake8.t b/tests/style/py-flake8.t
index 62fe19df..a6d859c7 100644
--- a/tests/style/py-flake8.t
+++ b/tests/style/py-flake8.t
@@ -27,7 +27,7 @@ my %skip =
 
 # my $cmd = shell_quote( 'flake8', '.' );
 my $cmd = shell_quote( 'flake8',
-    grep { not exists $skip{$_} } glob('./*.py ./scripts/*.py ./tests/board_gen/*.py ./pysollib/*.py ./pysollib/[cmgpuw]*/{*/*.py,*.py} ./pysollib/tile/*.py ./pysollib/tk/{[a-sw],ta,ti,to,tkhtml,tkstats}*.py ./pysollib/ui/tktile/*.py') );
+    grep { not exists $skip{$_} } glob('./*.py ./scripts/*.py ./tests/board_gen/*.py ./pysollib/*.py ./pysollib/[cmgpuw]*/{*/*.py,*.py} ./pysollib/tile/*.py ./pysollib/tk/{[a-sw],ta,ti,to,tkhtml,tkstats,tktree}*.py ./pysollib/ui/tktile/*.py') );
 
 # TEST
 eq_or_diff( scalar(`$cmd`), '', "flake8 is happy with the code." );