Memory leak using richTextCtrl and wxPython

Question

I have a problem with memory leaks for a application using wxPython and wx.richtext.RichTextCtrl. The application resembles this one - a simple digital clock on a window frame. In order to keep the code clean I use a different module to update the "text module" (ModuleClock.py).

Anyone that knows why it behaves like this?

I have also tried:

• Replacing the richtext with a StaticText-object (wx.StaticText). Result: doesn't consume memory.
• No call at all to ModuleClock.py. Result: doesn't consume memory.
• EDIT 1: Using the commands rto.Freeze(), rto.Thaw() and rto.BeginSupressUndo()
• EDIT 2: Moving the code from ModuleClock.py into Main.py (inside MainWindow.update method)

Main.py

import wx
import wx.richtext # as rt
import ModuleClock         #
from datetime import datetime
import os
import psutil

class MainWindow(wx.Frame):
    counter = 0
    lastcall = datetime.now()

    def __init__(self, parent):
        wx.Frame.__init__(self, parent, size=(600, 500), pos=(0, 0))

        self.panel = wx.Panel(self)
        self.panel.SetBackgroundColour('Black')

        self.clock = wx.richtext.RichTextCtrl(self.panel, wx.ID_ANY, value="", size = (600,150), style=wx.VSCROLL | wx.HSCROLL | wx.NO_BORDER)
        self.clock.SetBackgroundColour('Black')

        self.timer = wx.Timer(self)
        self.Bind(wx.EVT_TIMER, self.update, self.timer)
        self.timer.Start(100)
        self.Show()

    def update(self, event):
        now = datetime.now()
        self.counter = self.counter + 1

        ModuleClock.update(self.clock)

        # Check memory use by process every 30 seconds
        if (now - self.lastcall).seconds > 30:
            process = psutil.Process(os.getpid())
            print('memory use =', process.memory_info().rss/1000, 'kb')
            self.lastcall = now


app = wx.App(False)
frame = MainWindow(None)
app.MainLoop()

ModuleClock.py

from datetime import datetime


def update(rto):
    now = datetime.now()

    # default is black text
    rto.Clear()
    rto.BeginFontSize(16)
    rto.BeginTextColour("White")
    rto.WriteText(now.strftime("%A %d %B\n"))
    rto.BeginFontSize(36)
    rto.WriteText(now.strftime("%H:%M:%S"))

Command line output

(venv) C:\Users\Danne\PycharmProjects\Leak>python Main.py
memory use = 31920.128 kb
memory use = 32657.408 kb
memory use = 33492.992 kb
memory use = 34144.256 kb
memory use = 34975.744 kb
memory use = 35545.088 kb
memory use = 36376.576 kb
[30 records removed]
memory use = 58028.032 kb
memory use = 58871.808 kb
memory use = 59404.288 kb
memory use = 60268.544 kb
memory use = 60801.024 kb
memory use = 61607.936 kb

Answer 1

In ModuleClock you are never cancelling the changes to text colour or the font size i.e. for every Begin there is an End
Change ModuleClock to:

from datetime import datetime


def update(rto):
    now = datetime.now()

    # default is black text
    rto.Clear()
    rto.BeginFontSize(16)
    rto.WriteText(now.strftime("%A %d %B\n"))
    rto.EndFontSize()
    rto.BeginFontSize(36)
    rto.WriteText(now.strftime("%H:%M:%S"))
    rto.EndFontSize()

and add the line self.clock.BeginTextColour("White") after the self.clock.SetBackgroundColour('Black') in Main.py