This code works:
import tkinter
root = tkinter.Tk()
canvas = tkinter.Canvas(root)
canvas.grid(row = 0, column = 0)
photo = tkinter.PhotoImage(file = './test.gif')
canvas.create_image(0, 0, image=photo)
root.mainloop()
It shows me the image.
Now, this code compiles but it doesn't show me the image, and I don't know why, because it's the same code, in a class:
import tkinter
class Test:
def __init__(self, master):
canvas = tkinter.Canvas(master)
canvas.grid(row = 0, column = 0)
photo = tkinter.PhotoImage(file = './test.gif')
canvas.create_image(0, 0, image=photo)
root = tkinter.Tk()
test = Test(root)
root.mainloop()
The variable photo is a local variable which gets garbage collected after the class is instantiated. Save a reference to the photo, for example:
self.photo = tkinter.PhotoImage(...)
If you do a Google search on "tkinter image doesn't display", the first result is this:
Why do my Tkinter images not appear? (The FAQ answer is currently not outdated)
from tkinter import *
from PIL import ImageTk, Image
root = Tk()
def open_img():
global img
path = r"C:\.....\\"
img = ImageTk.PhotoImage(Image.open(path))
panel = Label(root, image=img)
panel.pack(side="bottom", fill="both")
but1 = Button(root, text="click to get the image", command=open_img)
but1.pack()
root.mainloop()
Just add global to the img definition and it will work
The problem is Python automatically deletes the references to the variable by a process known as Garbage Collection. The solution is to save the reference or to create a new reference.
The following are the ways:
Using self to increase the reference count and to save the reference.
import tkinter
class Test:
def __init__(self, master):
canvas = tkinter.Canvas(master)
canvas.grid(row = 0, column = 0)
self.photo = tkinter.PhotoImage(file = './test.gif') # Changes here
canvas.create_image(0, 0, image=self.photo) # Changes here
root = tkinter.Tk()
test = Test(root)
root.mainloop()
Saving it to a list to increase the reference count and to save the reference.
import tkinter
l=[]
class Test:
def __init__(self, master):
canvas = tkinter.Canvas(master)
canvas.grid(row = 0, column = 0)
photo = tkinter.PhotoImage(file = './test.gif')
l.append(photo)
canvas.create_image(0, 0, image=photo)
root = tkinter.Tk()
test = Test(root)
root.mainloop()
While using method 2, you can either make a global list as i did or use list inside the class. Both would work.
Some useful links:
About Garbage Collection 1
About Garbage Collection 2 (More useful)
As a rule of thumb, whenever you create your image in an indented block of code you need to safe a reference to that image. This is because of the python's automated garbage collection and it collects everything with a refcount of 0 when it destroys/leaves that frame/page/indented block of code.
The canonical way to deal with it is to have a list of images somewhere in the global namespace and add your image-references to that list. This is convenient but not very efficient and should be used for small applications.
import tkinter as tk
global_image_list = []
global_image_list.append(tk.PhotoImage(file = 'test.png'))
An more efficient way is to bound an attribute to your widget or class that holds that reference for you, as Bryan proposed in his answer. It doesn't make a difference if you do self.image or widget.image that was assigned widget = tk.Widget(.. before. But this also might not the right approach if you want to use that image further even when the widget is destroyed and garbage collected.
import tkinter as tk
root = tk.Tk()
label = tk.Label(root, text='test')
label.image = tk.PhotoImage(file = 'test.png')
label.configure(image=label.image)
Just add global photo as the first line inside the function.
In this code below, I made a simple route guidance by opening defined windows each time I press a specific button e.g.) Mainmenu -> Classroom Floor -> Classroom No.
I'm trying to make a 'Home' button that will close all open windows except for the first Main Menu window with WELCOME written.
For example, after I press btn7, btn702, then I have 4 windows open. I would like to add a 'Home' button that will close 3 newly open windows and leave the first window alive. How might I make this kind of button?
from os import system
from tkinter import *
from PIL import ImageTk, Image
mainmenu = Tk()
mainmenu.title("CAU 310 GUIDE MAP")
mainmenu.geometry("1280x800+0+0")
canvas = Canvas(mainmenu, width = 1280, height = 800)
canvas.pack(fill='both', expand = True)
canvas.create_text(640, 250, text = 'WELCOME', font=times 45)
btnclassroom = Button(mainmenu, padx=5, pady=5,text="Classroom", font="times 30", command=selectfloor)
btnclassroom.place(x=140, y=570)
def selectfloor():
mainmenu = Tk()
mainmenu.title("DESTINATION")
mainmenu.geometry("1280x800+0+0")
mainmenu.config(bg='white')
canvas = Canvas(mainmenu, width = 1280, height = 800)
canvas.pack(fill='both', expand = True)
canvas.create_text(640, 150, text = 'Select floor of classroom', font='Arial 40')
btn7=Button(mainmenu, padx=4, pady=4, text="7F", font="Arial 42 bold", command=floor7)
btn7.place(x=160-5, y=490)
def floor7():
mainmenu = Tk()
mainmenu.title("FLOOR 7")
mainmenu.geometry("1280x800+0+0")
canvas = Canvas(mainmenu, width = 1280, height = 800)
canvas.pack(fill='both', expand = True)
canvas.create_text(640, 150, text = 'Select classroom No.', font='Arial 40')
btn702=Button(mainmenu, padx=3, pady=3, text="No.702", font="Arial 38 bold", command=room702)
btn702.place(x=100+220*1, y=240)
mainmenu.mainloop()
def room702():
mainmenu = Tk()
mainmenu.title("Elevator 1")
mainmenu.geometry("1280x800+0+0")
lobby = ImageTk.PhotoImage(Image.open("1F_elevator1.jpg"), master=mainmenu)
canvas = Canvas(mainmenu, width = 1280, height = 800)
canvas.pack(fill='both', expand = True)
canvas.create_image(0, 0, image=lobby,anchor = "nw")
mainmenu.mainloop()
mainmenu.mainloop()
**I've been googling around for this kind of matter, and I think I've got a hint of making the 'selectfloor', 'floor7', 'room702' window as a children widget. But I'm still not sure how to make it happen.
You can store the windows in a list, and then iterate over the list to destroy them.
Here's a simplified example. This example uses Toplevel windows rather than instances of Tk. It's not clear why you're using multiple instances of Tk, but in general you should only ever have one. This same technique works with any sort of widgets, however.
import tkinter as tk
windows = []
def delete_all_but_first():
for window in windows[1:]:
window.destroy()
def new_window():
window = tk.Toplevel(root)
windows.append(window)
window.title(f"Window #{len(windows)}")
root = tk.Tk()
windows.append(root)
del_all = tk.Button(root, text="Delete all", command=delete_all_but_first)
new = tk.Button(root, text="New window", command=new_window)
new.pack(side="top", padx=20, pady=20)
del_all.pack(side="top", padx=20, pady=20)
root.mainloop()
There's an optimization you can make if you use Toplevel instead of Tk, and if you always make the windows direct children of the root window. In that case you can just iterate over all children of root, and delete any window that is a top-level.
In this case, you don't need to maintain the windows list.
def delete_toplevels():
for child in root.winfo_children():
if child.winfo_class() == "Toplevel":
child.destroy()
def new_window():
window = tk.Toplevel(root)
window.title(f"Window #{len(windows)}")
...
del_all = tk.Button(root, text="Delete all", command=delete_toplevels)
I have a question, its more an OS-based one.
I'm playing a video game and I want to be able to put a textual timer ontop of the game's screen as if it was a part of the game itself.
Now, I can write a program in any language that displays a TextBox with a timer on the screen, but if I run it, the game's process (lets call it game.exe) "loses" its focus and I get my TextBox focused and interactive by the OS.
Is there any option to display that text "ontop" of the game.exe that comes from an entire different process? as if there were "layers" to the screen. Also, this text shouldn't be intractable, clickable or make the game.exe process lose its focus.
Here's a very simple example I drew:
Thanks a lot!
Solved this using a window trick with python and tkinter with some windows api stuff.
The trick is to create a transparent non-clickable window and keep it always on top.
I've basically combined this answer with a bunch of simpler stuff like removing window's border and set to auto fullscreen.
from tkinter import *
import time
import win32gui
import win32api
from win32api import GetSystemMetrics
# WIDTH = 500
# HEIGHT = 500
WIDTH = GetSystemMetrics(0)
HEIGHT = GetSystemMetrics(1)
LINEWIDTH = 1
TRANSCOLOUR = 'gray'
title = 'Virtual whiteboard'
global old
old = ()
global HWND_t
HWND_t = 0
tk = Tk()
# tk.title(title)
tk.lift()
tk.wm_attributes("-topmost", True)
tk.wm_attributes("-transparentcolor", TRANSCOLOUR)
tk.attributes('-fullscreen', True)
state_left = win32api.GetKeyState(0x01) # Left button down = 0 or 1. Button up = -127 or -128
canvas = Canvas(tk, width=WIDTH, height=HEIGHT, highlightthickness=0)
canvas.pack()
canvas.config(cursor='tcross')
canvas.create_rectangle(0, 0, WIDTH, HEIGHT, fill=TRANSCOLOUR, outline=TRANSCOLOUR)
canvas.create_text(WIDTH/2,HEIGHT/2,fill="white",font="Arial 20", text="TEXT GOES HERE")
def putOnTop(event):
event.widget.unbind('<Visibility>')
event.widget.update()
event.widget.lift()
event.widget.bind('<Visibility>', putOnTop)
def drawline(data):
global old
if old !=():
canvas.create_line(old[0], old[1], data[0], data[1], width=LINEWIDTH)
old = (data[0], data[1])
def enumHandler(hwnd, lParam):
global HWND_t
if win32gui.IsWindowVisible(hwnd):
if title in win32gui.GetWindowText(hwnd):
HWND_t = hwnd
win32gui.EnumWindows(enumHandler, None)
tk.bind('<Visibility>', putOnTop)
tk.focus()
running = 1
while running == 1:
try:
tk.update()
time.sleep(0.01)
if HWND_t != 0:
windowborder = win32gui.GetWindowRect(HWND_t)
cur_pos = win32api.GetCursorPos()
state_left_new = win32api.GetKeyState(0x01)
if state_left_new != state_left:
if windowborder[0] < cur_pos[0] and windowborder[2] > cur_pos[0] and windowborder[1] < cur_pos[1] and windowborder[3] > cur_pos[1]:
drawline((cur_pos[0] - windowborder[0] - 5, cur_pos[1] - windowborder[1] - 30))
else:
old = ()
except Exception as e:
running = 0
print("error %r" % (e))
Ok, so I've been tasked with creating a VERY simple GUI at work (I'm an intern). The task is to eventually connect to a machine and process real data, but right now I'm working on randomly generated sine data with noise. I've chose to work in Python 3.0, and use wxpython to create my GUI components.
As I want everything to appear on the same window, I'm using panels (hence wx.lib.plot.PlotCanvas rather than something like matplotlib.pyplot)
The problem that I have is that over time, the plot seems to 'expand' off of the panel. This is temporarily solved when I manually resize the window, but resumes again immediately after (you need to run the code to see what I mean).
Expansion over time in panel
Another problem (that has bugged me since I have started writing the code) is that sometimes when I resize the window (manually) or minimize it and then maximize it again, the timer randomly starts and stops.
I have tried all sorts of things (changing padding in sizers, extra arguments, changing time between refreshes GetBestSize()) but I believe that I simply don't understand wxpython well enough to identify where the problem is
I would really appreciate any help you can shed on either of these problems (I don't know, they might even be linked to each other).
FYI: I am not an experienced coder, and my code is not finished (I have more functions to code, but I feel like I should resolve this first). I have constructed this code by looking at different techniques from various tutorials and websites like stackoverflow, so I know it's not formatted well and could definitely be made more efficient. Also, I have removed some parts just to be safe about confidentiality - nothing important, just strings in messages.
PS: If you do have an easier way to do the whole plot/update thing that doesn't have this problem (preferably still in wx) I would be thrilled to hear that as well
And here's my code:
EDIT: Solved the expanding problem by using self.p2.SetSize((W+0,L+0)) instead of (self.p2.GetBestSize())
EDIT: Made transitions much smoother by just regenerating data and redrawing it on existing canvas in the evt_timer function (instead of recreating the whole canvas, which gave a blink-y appearance if you know what I mean)
import wx
import numpy as np
import matplotlib.pyplot as plt
from scipy.optimize import leastsq
import wx.lib.plot as plot
import time
import os
wildcard = "Text File (*.txt)|*.txt|"\
"Picture (*.png)|*.png|"\
"All files (*.*)|*.*"#This wildcard shows the options for file endings in the "SAVE" tab - see OnSave(self,event)
wildcard2 = "Picture (*.png)|*.png|"\
"Text File (*.txt)|*.txt|"\
"All files (*.*)|*.*"
class PlotCanvas(plot.PlotCanvas):
def __init__(self,parent,id,size,accepted):
"""
This randomly generates sine data (with noise) and plots it to a panel.
Incorporated as a separate class instead of instatiating it as a plot.PlotCanvas object
to overcome an issue of the size of the plot in the panel.
"""
plot.PlotCanvas.__init__(self,parent,id,style=wx.BORDER_SUNKEN,size = size)
N = 100 # number of data points
self.t = np.linspace(0, 4*np.pi, N)
f = 1.15247 # Optional!! Advised not to use
self.data = 3.0*np.sin(f*self.t+0.001) + 0.5 + np.random.randn(N) # create artificial data with noise
guess_mean = np.mean(self.data)
guess_phase = 0
guess_freq = 1
guess_amp = 1
optimize_func = lambda x: x[0]*np.sin(x[1]*self.t+x[2]) + x[3] - self.data
est_amp, est_freq, est_phase, est_mean = leastsq(optimize_func, [guess_amp, guess_freq, guess_phase, guess_mean])[0]
fine_t = np.arange(0,max(self.t),0.1)
data_fit=est_amp*np.sin(est_freq*fine_t+est_phase)+est_mean
multiplier = 1
dataset1 = [(x,[d for d in self.data][[td for td in self.t].index(x)])for x in [td for td in self.t]]
fitdata1 = [(x,[df for df in data_fit][[tf for tf in fine_t].index(x)]) for x in [tf for tf in fine_t]]
dataset =[(x,y*multiplier) for (x,y) in dataset1]
fitdata = [(x,y*multiplier) for (x,y) in fitdata1]
self.data = dataset
self.data2 = fitdata
line = plot.PolyLine(self.data,legend = 'random',colour = 'light blue', width =2)
line2 = plot.PolyLine(self.data2,legend = 'sineline',colour ='black',width =2)
a = []
if "D" in accepted:
a.append(line)
if "S" in accepted:
a.append(line2)
if "G" in accepted:
pass
if "L" in accepted:
pass
gc = plot.PlotGraphics(a,'Line Graph','X','Y')
xmin = self.t[0]-0.01*(self.t[-1]-self.t[0])
xmax = self.t[-1]+0.01*(self.t[-1]-self.t[0])
self.Draw(gc,xAxis=(xmin,xmax),yAxis=(min([x[1] for x in dataset])-0.01*(max([x[1] for x in dataset])-min([x[1] for x in dataset])),
max([x[1] for x in dataset])+0.01*(max([x[1] for x in dataset])-min([x[1] for x in dataset]))))
#self.showLegend = True
#self.enableZoom = True
def Dialog(self, parent, message, c):# Will be used to notify the user of errors/processes
if c == "W":
caption = "Warning!"
dlg = wx.MessageDialog(parent, message, caption, wx.OK | wx.ICON_WARNING)
elif c == "I":
caption = "Information"
dlg = wx.MessageDialog(parent, message, caption, wx.OK | wx.ICON_INFORMATION)
dlg.ShowModal()
dlg.Destroy()#Destroys dialog on close
class Frame(wx.Frame):
"""
This is the main class. In it, we declare the separate panels, canvas, menubar, buttons and sizers.
"""
def __init__(self,parent,id,title):
wx.Frame.__init__(self, parent, id, title, wx.DefaultPosition)
self.CurrentDirectory = os.getcwd()
self.timer=wx.Timer(self)#Instantiating the timer
self.count=0
self.Bind(wx.EVT_TIMER,self.evt_timer)#Binding it to itself so that it is always triggered
self.Bind(wx.EVT_PAINT,self.paint)
menubar = wx.MenuBar()
fileMenu = wx.Menu() #Creating the Menubar at the top
#Creating 3 menus: fileMenu,fit,and help
save = wx.Menu()
z = wx.MenuItem(save,wx.ID_ANY,'Save Raw Data\tCtrl+D')
self.Bind(wx.EVT_MENU,self.OnSave,z)
save.Append(z)
z= wx.MenuItem(save,wx.ID_ANY,'Save Image\tCtrl+I')
self.Bind(wx.EVT_MENU,self.OnSaveImage,z)
save.Append(z)
fileMenu.AppendSubMenu(save,'&Save')
fileMenu.AppendSeparator()
z = wx.MenuItem(fileMenu, wx.ID_EXIT, '&Quit\tCtrl+W')
self.Bind(wx.EVT_MENU, self.OnQuit, z)
fileMenu.Append(z)
fit = wx.Menu()#Making a check menu
self.gaussian = fit.Append(wx.ID_ANY,'Gaussian',kind = wx.ITEM_CHECK)
#self.Bind(wx.EVT_MENU,self.ToggleGaussian,self.gaussian)
fit.Check(self.gaussian.GetId(),False)
self.sine = fit.Append(wx.ID_ANY,'Sine',kind = wx.ITEM_CHECK)
#self.Bind(wx.EVT_MENU,self.ToggleSine,self.sine)
fit.Check(self.sine.GetId(),False)
self.linear = fit.Append(wx.ID_ANY,'Linear',kind=wx.ITEM_CHECK)
#self.Bind(wx.EVT_MENU,self.ToggleLinear,self.linear)
fit.Check(self.linear.GetId(),False)
help = wx.Menu()
z = wx.MenuItem(help,wx.ID_ANY,'&About\tCtrl+H')
self.Bind(wx.EVT_MENU,self.OnHelp,z)
help.Append(z)
menubar.Append(fileMenu, '&File')
menubar.Append(fit, '&Fit')
menubar.Append(help, '&Help')#adding menus to menubar
self.SetMenuBar(menubar)#formatting the frame with menubar
self.sp = wx.SplitterWindow(self)#Splitting the window into 2 panels
self.p1 = wx.Panel(self.sp,style = wx.SUNKEN_BORDER)#For buttons and user events
self.p2 = wx.Panel(self.sp,style = wx.SUNKEN_BORDER)#For display of the plot
self.sp.SplitVertically(self.p1,self.p2,300)
sizer = wx.GridBagSizer(3, 3)#Versatile sizer for layout of first panel self.p1
bitmappath = self.CurrentDirectory + "\\BITMAPS"
bmp = wx.Bitmap(bitmappath+"\\SAVE.BMP",wx.BITMAP_TYPE_BMP)
self.saveBtn = wx.BitmapButton(self.p1,wx.ID_ANY,bitmap = bmp,size =(bmp.GetWidth()+10,bmp.GetHeight()+10))
self.Bind(wx.EVT_BUTTON,self.OnSave,self.saveBtn)
sizer.Add(self.saveBtn, (0, 0), wx.DefaultSpan, wx.ALL,5)
bmp = wx.Bitmap(bitmappath +"\\START.BMP",wx.BITMAP_TYPE_BMP)
self.startBtn = wx.BitmapButton(self.p1,-1,bitmap = bmp,size =(bmp.GetWidth()+10,bmp.GetHeight()+10))# A button that starts and stops the plotting
self.startBtn.startval = "START"
self.Bind(wx.EVT_BUTTON,self.paint,self.startBtn)
sizer.Add(self.startBtn, (0, 1), wx.DefaultSpan,wx.ALL,5)
sizer1 = wx.BoxSizer(wx.VERTICAL)
W,L = self.p2.GetSize()
self.p2.canvas = PlotCanvas(self.p2,wx.ID_ANY,(W,L),["D"])
sizer1.Add(self.p2.canvas,1,wx.ALL,0,0)
self.p2.SetSizerAndFit(sizer1)
self.p1.SetSizerAndFit(sizer)
self.p2.SetSizerAndFit(sizer1)
self.p2.SetSize(W,L)
self.Maximize(True)
self.Centre()
self.Show()
############### event methods ###########
def paint(self,event):
"""
Updates the canvas based on the value of the startbtn(not the image). Bound to self.timer.
"""
bitmappath = self.CurrentDirectory + "\\BITMAPS"
if self.startBtn.startval == "START":
self.timer.Start(1)# increase the value for more time
bmp = wx.Bitmap(bitmappath + "\\STOP.BMP",wx.BITMAP_TYPE_BMP)
self.startBtn.SetBitmap(bmp)
self.startBtn.startval = "STOP"
elif self.startBtn.startval == "STOP":
self.timer.Stop()
bmp = wx.Bitmap(bitmappath+ "\\START.BMP",wx.BITMAP_TYPE_BMP)
self.startBtn.SetBitmap(bmp)
self.startBtn.startval = "START"
def evt_timer(self,event):
self.count +=1
if self.count== 10:# By increasing count (or the number in self.timer.Start()) you can increase the interval between updates
#self.p2.canvas.Clear()
sizer1 = wx.BoxSizer(wx.VERTICAL)
W,L = self.p2.GetSize()
a = ["D"]
if self.sine.IsChecked():
a.append("S")
elif self.linear.IsChecked():
a.append("L")
elif self.gaussian.IsChecked():
a.append("G")
self.p2.canvas = PlotCanvas(self.p2,wx.ID_ANY,(W,L),a)
sizer1.Add(self.p2.canvas,1,wx.ALL,0,0)
self.p2.SetSizerAndFit(sizer1)
self.p2.SetSize(self.p2.GetBestSize())
self.count=0 # reset the count
def Dialog(self, parent, message, c):# Will be used to notify the user of errors/processes
if c == "W":
caption = "Warning!"
dlg = wx.MessageDialog(parent, message, caption, wx.OK | wx.ICON_WARNING)
elif c == "I":
caption = "Information"
dlg = wx.MessageDialog(parent, message, caption, wx.OK | wx.ICON_INFORMATION)
dlg.ShowModal()
dlg.Destroy()#Destroys dialog on close
def OnSave(self,event):#Triggered by menubar and button
try:
rawdata = self.p2.canvas.data
raw_X =[x[0] for x in rawdata]
raw_Y =[x[1] for x in rawdata]
dlg = wx.FileDialog(#Code for this from http://www.blog.pythonlibrary.org
self, message="Save file as ...",
defaultDir=self.CurrentDirectory,
defaultFile=str(time.ctime()), wildcard=wildcard, style=wx.FD_SAVE
)
if dlg.ShowModal() == wx.ID_OK:
path = dlg.GetPath()
dlg.Destroy()
f = open(path+".txt","w+")
for i in range(len(raw_X)):
f.write(str(raw_X[i])+"\t"+str(raw_Y[i])+"\n")
f.close()
self.Dialog(None,"File successfully saved","I")
except UnboundLocalError:#Catch error when user closes save window without selecting any directory or filename
pass
def OnSaveImage(self,event):
try:
rawdata = self.p2.canvas.data
raw_X = [x[0] for x in rawdata]
raw_Y = [x[1] for x in rawdata]
dlg = wx.FileDialog(
self, message="Save file as ...",
defaultDir=self.CurrentDirectory,
defaultFile=str(time.ctime()), wildcard=wildcard2, style=wx.FD_SAVE
)
if dlg.ShowModal() == wx.ID_OK:
path = dlg.GetPath()
dlg.Destroy()
fig1 = plt.figure()
plt.plot(raw_X,raw_Y)
plt.title("Raw Data")
fig1.savefig(path+".png")
self.Dialog(None,"File successfully saved","I")
except UnboundLocalError:
pass
def OnMultiply(self,e):
try:
factor = self.x.GetValue()
factor = float(factor)
self.IntegrationTime = factor
except ValueError as e:
self.Dialog(None,str(e),"W")
def OnQuit(self, e):
self.Close()
def OnHelp(self,e):
self.Dialog(None,"N/A","I")
def ToggleSine(self,e):
pass
def ToggleLinear(self,e):
self.Dialog(None,"Not added yet","W")
def ToggleGaussian(self,e):
self.Dialog(None,"Not added yet","W")
if __name__ =="__main__":
app=wx.App()
Frame(None,-1,"N/A")
app.MainLoop()
I am building an application to continuously display an image fetched from an IP camera. I have figured out how to fetch the image, and how to also display the image using Tkinter. But I cannot get it to continuously refresh the image. Using Python 2.7+.
Here is the code I have so far.
import urllib2, base64
from PIL import Image,ImageTk
import StringIO
import Tkinter
URL = 'http://myurl.cgi'
USERNAME = 'myusername'
PASSWORD = 'mypassword'
def fetch_image(url,username,password):
# this code works fine
request = urllib2.Request(url)
base64string = base64.encodestring('%s:%s' % (username, password)).replace('\n', '')
request.add_header("Authorization", "Basic %s" % base64string)
result = urllib2.urlopen(request)
imgresp = result.read()
img = Image.open(StringIO.StringIO(imgresp))
return img
root = Tkinter.Tk()
img = fetch_image(URL,USERNAME,PASSWORD)
tkimg = ImageTk.PhotoImage(img)
Tkinter.Label(root,image=tkimg).pack()
root.mainloop()
How should I edit the code so that the fetch_image is called repeatedly and its output updated in the Tkinter window?
Note that I am not using any button-events to trigger the image refresh, rather it should be refreshed automatically, say, every 1 second.
Here is a solution that uses Tkinter's Tk.after function, which schedules future calls to functions. If you replace everything after your fetch_image definition with the snipped below, you'll get the behavior you described:
root = Tkinter.Tk()
label = Tkinter.Label(root)
label.pack()
img = None
tkimg = [None] # This, or something like it, is necessary because if you do not keep a reference to PhotoImage instances, they get garbage collected.
delay = 500 # in milliseconds
def loopCapture():
print "capturing"
# img = fetch_image(URL,USERNAME,PASSWORD)
img = Image.new('1', (100, 100), 0)
tkimg[0] = ImageTk.PhotoImage(img)
label.config(image=tkimg[0])
root.update_idletasks()
root.after(delay, loopCapture)
loopCapture()
root.mainloop()