How do I dynamically set the name of a tkinter label - python-3.x

I have this code in my project:
def savespack():
savelabelcount = 0
for i in range(saveamount):
savelabelcount = savelabelcount + 1
savebuttontext = "Save " + str(savelabelcount)
Button(scrollable_frame, text=savebuttontext, width="53", height="5").pack()
The user can create multiple saves in the program, and when the project is reopened, the correct amount of save files will be shown as Tkinter buttons. I've created the buttons by reading a number from an external file. I need to make the buttons have different variable names to call the correct save file and load the correct properties when a button is pressed (for example "Save 2" needs to load save2.txt's properties)
Simply put I need to give Button(scrollable_frame, text=savebuttontext, width="53", height="5").pack() a new variable name for each iteration of the loop, I dont know how to do this. I read something about dictionaries and lists but it was very confusing and I dont know if it can be applied in this situation.
The variable names should be something like: savebutton1, savebutton2, savebutton3 etc.
Any way I could do this would be appreciated, thanks!

The example below shows how to save each button widget inside a list rather than as separate variables.
It also will call the saveFile function when the button is pressed which currently just prints to the screen the save file number but this function could be replaced with the code that actually saves each file. With this method, it might not even be necessary to keep the buttons in a list.
I'd normally do this using classes rather than globals but this will work for your purposes
import tkinter as tk
saveamount = 5
save_buttons = []
def saveFile(fileNumber):
print("Saving File ", fileNumber)
def savespack():
global save_buttons
savelabelcount = 0
for i in range(saveamount):
savelabelcount = savelabelcount + 1
savebuttontext = "Save " + str(savelabelcount)
currentButton = tk.Button(scrollable_frame, text=savebuttontext, width="53", height="5")
currentButton['command'] = lambda x=savelabelcount: saveFile(x)
currentButton.pack()
save_buttons.append(currentButton)
root = tk.Tk()
scrollable_frame = tk.Frame(root)
scrollable_frame.pack()
savespack()
root.mainloop()
You could use a dictionary rather than a list but given your use case, I'm not sure there is any benefit. Just use save_buttons[2] to access the third button.

Related

Efficiently create tkinter images using a loop

Currently I loop through a list of image names and make them into a tkinter PhotoImage. These are saved as variables under their respective names from the list using vars()[var].
In this case vars()[var] represents the value of the item in a list making it into a variable name for the images.
example shown below:
list = ["a","b","c","d"] #and so on...
image_id = []
for x in range((len)list):
var = list[x]
vars()[var] = tk.PhotoImage(file = var + ".gif")
image_id.append(vars()[var]) #this adds the identity of all photoimages to a list for later use
According to my tests I can use the images via the variable names or identities as long as it is within the same function. This is due to the variables being local.
The problem is that even though the image identities are in a list they do not work when used outside of the original function. I believe this happens because the images are tied to their variable names and since those are all local tkinter garbage collects them resulting in my error which is "pyimagenumber does not exist." This is because the identity for a tkinter image is just "pyimage" and its corresponding number. My line of thinking is that I want to make all variable names that store images to be global without needing an extra line per image since that defeats the purpose of using a loop and list. Is there any way i can set the "vars()[var]" to be global while also giving it a value?
For any solutions I would like to avoid fundamental changes or using pillow.
Any help is appreciated and if you have further questions about context please ask!
Simply move your empty list outside of your function. Also instead of for x in range(len(list)), use for x in something instead. It could be something like this:
import tkinter as tk
root = tk.Tk()
image_id = []
def image_creation():
imlist = ["a","b","c","d"] #don't name it as list - it shadows the built in list
for var in imlist:
image_id.append(tk.PhotoImage(file = var + ".gif"))
... #the rest of your code
root.mainloop()
There's no need to use vars(). Just create a dictionary in the global namespace and add your images to it. You can even use the original item from the list as the key.
Example:
global images
...
list = ["a","b","c","d"]
images = {}
for x in list:
images[x] = tk.PhotoImage(file = var + ".gif")
Then, the image for "a" can be accessed at any time as images['a'].

Python 3.7 + tkInter : How can I make sure a button is assigned an individual function from a file?

I am having some issues wrapping my head around something I encountered in python recently.
So, basically, I want to allow for a user to load several json files, all listed in a python list. These files contain parameters used to create buttons with, namely, the color the button should have, the text that should be displayed in it and the command that it needs to execute once clicked.
def createTags(self):
for items in self.LoadedInstallProfiles:
with open(items, "r") as jsonfiles:
self.loadeddata = json.load(jsonfiles)
self.tag = Button(self.tagmenu, text=self.loadeddata.get("profilename"), background=
self.loadeddata.get("profilecolor"), command=print(self.loadeddata.get("profilename")))
self.tag.pack(side="top",fill="x")
The problem is: the buttons show up with their individual color and text, but all seem to print out the same profilename when clicked, which is that in the last json file in the list.
I common way is to store the created button widgets in a list. I have modified your method. See below.
def createTags(self):
# First create the widget and append to list variable
self.tags = [] #List to store button widgets
for items in self.LoadedInstallProfiles:
with open(items, "r") as jsonfiles:
loadeddata = json.load(jsonfiles)
text = loadeddata.get("profilename")
bg = loadeddata.get("profilecolor")
tag = Button( self.tagmenu, text=text, background=bg, command=print(text) )
self.tag.append( tag )
# Then display the widgets
for tag in self.tags:
tag.pack(side="top",fill="x")
I imagine the problem with command=print(self.loadeddata.get("profilename")) is similar to the problem with lambda statements (that said I am surprised your buttons work at all They should print once at init and then never work after that because you are calling print at button creation instead of saving a reference to print).
Due to the nature of how lambda works here in a loop like this you end up only printing the last value in the loop for all commands. Instead you need to use a lambda statement and also define the value in the lambda for each loop to accurately record the correct data for the print statement.\
I created 3 test files for this:
test.json:
{"profilename":"test", "profilecolor": "green"}
test2.json:
{"profilename":"test2", "profilecolor": "blue"}
test3.json:
{"profilename":"test3", "profilecolor": "orange"}
Example code:
import tkinter as tk
import json
class Window(tk.Tk):
def __init__(self):
super().__init__()
self.btn_list = []
for file in ['test.json', 'test2.json', 'test3.json']:
with open(file, 'r') as f:
self.btn_list.append(json.load(f))
self.create_tags()
def create_tags(self):
for item in self.btn_list:
tk.Button(self, text=item.get("profilename"), background=item.get("profilecolor"),
command=lambda x=item.get("profilename"): print(x)).pack(side="top", fill="x")
if __name__ == '__main__':
Window().mainloop()
Results:

Ever expanding amount of Entries with TKinter

What I'm trying to do is to make a GUI where when you start typing in an entry-box another shows up just beneath the one you are typing in. Then when you start typing in the one that popped up, another pops up. Is this possible with TKinter and Python?
Edit:
So what I currently have is this:
entry1 = StringVar()
numberLabel3 = Label(window, text = "3. External meeting attendees")
r+=1
numberLabel3.grid(column = 0, row = r, sticky = W)
externalAtendeesLabel = Label(window, text = "input name of external meeting atendee: ")
r+=1
externalAtendeesLabel.grid(column = 1, row = r, sticky = E)
externalAtendeesEntry = Entry(window, textvariable = entry1)
externalAtendeesEntry.grid(column = 2, row = r)
#Note to self: Find a smart way of dynamically expanding this "list" of entries
(There is more code above and below this, but this is the relevant code for my question)
where r is a variable I made to make it easier to insert stuff into the middle of my rather long code.
The imports I'm using are:
from tkinter import *
from PIL import ImageTk
from PIL import Image
import os
I use the image modules and OS to insert an image further up in my GUI.
What I was thinking was to make a function that I could somehow setup to check the newest Entry-box, but I've run into the problem that for this to be potentially infinite I would have to dynamically create new variables, so that I can access the information that the user inputs. These variables would save the info just like my entry1 variable does it for the externalAtendeesEntry.
I would also have to dynamically make variables for more entries.
How do I dynamically create a potentially infinite amount of variables?
I know that this is kind of a re-post, but the other ones I've found all say that you should use dictionaries, but in that case it can't be infinite. It can only be finite to the point where my dictionary is no longer.
For one, you don't need to use StringVar. It only complicates your code without providing any real value. The other part of the answer is to store the entries in a list.
For example, create a function called addEntry that creates an entry and adds it to a list:
entries = []
...
def addEntry():
entry = tk.Entry(...)
entry.pack(...)
entries.append(entry)
To get the values at a later date, just iterate over the list:
for entry in entries:
print(entry.get())
With that, you can add entries whenever you want. You could, for example, bind to <Any-KeyRelease> to create a new entry as the user types (being sure to only do it if there isn't already a blank entry). Or, bind to <Return> or <FocusOut>, or on the click of a "new person" button, or however else you decide.

Label keeps on appearing

SO I am using Python 3.4 and tkinter.
And when I call a function again n again which contains a label, the label keeps on appearing in window but previous label doesn't go away?
How can I remove any printed label from GUI window as soon as function is called and then display new one?
Here is the code:-
#def prestart():
#here I check if number of match is okay, if not, user is redirected to setting else, I call start()
def start():
#CPU Choice
cpu_choice = Label(historyframe, text = "CPU Choosed: {}".format(dict['cpu_choice']))
#Played Match
#played_num_of_match = Label(scoreframe, text = "Number of Matches Played: {}".format(int(dict['match_played'])))
#Display Status
status_disp = Label(scoreframe, text = "Current Status: {}".format(dict['status']))
if(int(dict['match_played']) < int(dict['num_of_match'])):
playframe.grid(row = 1, column = 0)
historyframe.grid(row = 2, column = 1)
status_disp.pack(fill=X)
elif(int(dict['match_played']) == int(dict['num_of_match'])):
playframe.grid(row = 1, column = 0)
historyframe.grid(row = 2, column = 1)
status_disp.pack(fill=X)
cp = dict['cpu_point']
up = dict['user_point']
result(cp, up)
cpu_choice.pack(fill = X)
scoreframe.grid(row = 2, column = 0)
This function just updates the display!
def send_value(x):
#Here I run logic of game and change value of key in dictionary and call start() at end of change.
Now, the choice buttons are not in any definition as they don't need to be called again n again. I just make playframe disappear n appear!
Here is the code for them:-
#Display Question
question = Label(playframe, text = "Rock? Paper? Scissor?")
#Rock
rock = Button(playframe, text = "Rock!", command = lambda: send_value("ROCK"))
#Paper
paper = Button(playframe, text = "Paper!", command = lambda: send_value("PAPER"))
#Scissor
scissor = Button(playframe, text = "Scissor!", command = lambda: send_value("SCISSOR"))
So when user clicks Rock/Paper/Scissor, I just change key value in dictionary! But if I keep the label outside function, it doesn't get auto updated!
Everything else is working perfectly. I'll kind of now start to make code cleaner.
Try something like this instead of creating a new label every time:
import Tkinter as tk
class Window():
def __init__(self, root):
self.frame = tk.Frame(root)
self.frame.pack()
self.i = 0
self.labelVar = tk.StringVar()
self.labelVar.set("This is the first text: %d" %self.i)
self.label = tk.Label(self.frame, text = self.labelVar.get(), textvariable = self.labelVar)
self.label.pack(side = tk.LEFT)
self.button = tk.Button(self.frame, text = "Update", command = self.updateLabel)
self.button.pack(side = tk.RIGHT)
def updateLabel(self):
self.i += 1
self.labelVar.set("This is new text: %d" %self.i)
root = tk.Tk()
window = Window(root)
root.mainloop()
Important points:
1) A class is used, as it is much easier to pass values around when all Tkinter objects and variables are member variables, accessible from all of your GUI functions.
2) updateLabel does not create a new Label. It simply updates the StringVar() object to hold new text every time you call the function. This is accomplished with the textvariable = self.labelVar keyword when creating my Label widget.
PS: This is done in Python 2.5 so for this code to work for you, change Tkinter to tkinter
EDIT 06/19/2015:
If you want to implement something similar to what I have with your code, without using a class, you'll need to pass around references to your variables.
1) Change start:
Your Labels cpu_choice, status_disp, etc. should be created outside of the function; likely in the same location as question, rock, paper, scissors, etc. You will also pack them outside of the function as well. Same with all the calls to .grid inside of start; you shouldn't need to call pack or grid more than once: right when you create the widget.
The following lines:
playframe.grid(row = 1, column = 0)
historyframe.grid(row = 2, column = 1)
status_disp.pack(fill=X)
Can be done outside of the function as well; you execute these 3 statements under both the if and the elif conditions. This means they aren't really conditional statements; they are done regardless of the validity of the condition.
2) Create a StringVar for both cpu_choice & status_disp & edit the Labels as follows (remember, outside of the function):
cpu_choice_text = StringVar()
cpu_choice_text.set("Set this to whatever is shown at the start of the game")
cpu_choice = Label(historyframe, text = cpu_choice_text.get(), textvariable = cpu_choice_text)
cpu_choice.pack(fill = X)
# And do this same thing for status_disp
3) When you call start, you will now pass it cpu_choice_text & status_disp_text (or whatever they are called). Instead of trying to change the text field of the Label frame, you may now use a set call on the StringVar which is connected to the Label & the Label will automatically update. Example:
def start(cpu_choice_text, status_disp_text):
cpu_choice.set(text = "CPU Choice: {}".format(dict['cpu_choice']))
...
Alternatively, wrap it all in a class and make it much easier for yourself by using self on every Tkinter variable & widget. In this way you won't need to pass variables to your functions, just access member variables directly as I have with self.i, self.labelVar in my example.
Each time you call start you create new labels and use grid to place them in the same spot as the old labels. The best solution is to only create the labels once, but if you insist on creating new labels each time start is called, you need to delete the old labels first.
You can use the destroy() method of a label to destroy it, though for that to work you must keep a global reference of the label.

Saving StringVars to text and problems with globals

This is my first project with tkinter and I'm having some problems with StringVars. I am trying to create a program where a user can input information and then it will save it to a txt document, the simplified code is.
def New_Condition():
def Global_Vars():
global Str_Name
Str_Name = StringVar()
global Str_Eff
Str_Eff = StringVar()
Global_Vars()
Gui = Tk()
def Save_Condition():
CND_InfoList = [StringVar.get(Str_Name),StringVar.get(Str_Eff)]
TXT_CND = open("C:\\Users\\Clark\\DnD\\Conditiontxt\\Conditions.txt","a")
TXT_CND.write("$".join(CND_Info_List) + "$\n")
TXT_CND.close()
Name = Entry(textvariable = Str_Name).pack()
Eff = Entry(textvariable = Str_Eff).pack()
Save = Button(text = "Save",command = Save_Condition).pack()
Gui.mainloop()
The program will save to a textfile but it only saves blanks and not the user input in the entry boxes.
I'm not sure if the error is with the way I'm declaring global variables or if it is with the StringVar itself. Thanks for any help.
The crux of the problem is that you're creating the instances of StringVar before creating the instance of Tk. You must always initialize tkinter before creating widgets or StringVars. When I move Gui = Tk() before creating the StringVar, your code works.
According to some comments to your original question, you say you are creating multiple instances of Tk. This can also cause unexpected problems. If you need to create additional windows you need to be creating instances of Toplevel rather than Tk. Your program should always have exactly once instance of Tk, and it needs to be created before any other Tkinter objects.

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