In Python/Tkinter, I am trying to get a value (integer) from a frame, do a calculation on it and return it as an output. I was able to make it work when using only a master frame and putting everything in that one frame. Now I want to separate it and another operation into their own frames.
My program converts board feet to Lineal feet (frame A) and
Lineal feet to board feet (frame B).
I get errors like: NameError: global name 'b_entry' is not defined. I have a feeling I might be doing things like referencing frames (self, master, a_frame, etc.) improperly.
Here's a simple example:
import Tkinter as tk
class App:
def __init__(self, master):
self.master = master
master.grid()
b_frame = tk.Frame(master).grid(row=0)
b_name = tk.Label(b_frame, text='Blah').grid(row=1, columnspan=4)
b_label = tk.Label(b_frame, text='Label').grid(row=2, column=0)
b_entry = tk.Entry(b_frame).grid(row=2, column=1)
b_output = tk.Label(b_frame, text='Output')
b_output.grid(row=3, columnspan=2)
b_button = tk.IntVar()
tk.Button(b_frame, text='calc', command=self.convert).grid(row=4, columnspan=2)
def convert(self):
a = int(b_entry.get())
result = int(a * a)
b_output.configure(text=result)
root = tk.Tk()
App(root)
root.mainloop()
I see two issues.
You should not assign a widget to a variable and pack/grid it on the same line. This causes the variable to have a value of None, because that's what pack and grid return. This will screw up your widget hierarchy because when b_frame is None, tk.Label(b_frame, ... will make the label a child of the Tk window instead of the Frame.
If you want a variable to be visible in all of a class' methods, you should assign it as an attribute of self.
So you should change lines like
b_entry = tk.Entry(b_frame).grid(row = 2, column = 1)
To
self.b_entry = tk.Entry(b_frame)
self.b_entry.grid(row = 2, column = 1)
Then you will be able to properly reference the entry in convert.
a = int(self.b_entry.get())
Related
I'm trying to create a page that outputs a large amount of data, and wraps the text dynamically depending on window size. I started by setting wraplength = self.master.winfo_width(), which sets the text wrapping to the current window size, but it does not change when the window does. I found this answer, which seemed like it would solve the problem, but when trying to recreate it myself, something went wrong. I suspect that I'm misunderstanding something with .bind or <Configure>, but I can't be sure. My base code is as follows:
from tkinter import *
class Wrap_example(Frame):
def __init__(self):
Frame.__init__(self)
self.place(relx=0.5, anchor='n')
#Initalize list and variable that populates it
self.data_list = []
self.data = 0
#Button and function for creating a bunch of numbers to fill the space
self.button = Button(self, text = "Go", command = self.go)
self.button.grid()
def go(self):
for self.data in range(1, 20000, 100):
self.data_list.append(self.data)
#Label that holds the data, text = list, wraplength = current window width
self.data = Label(self, text = self.data_list, wraplength = self.master.winfo_width(), font = 'arial 30')
self.data.grid()
#Ostensibly sets the label to dynamically change wraplength to match new window size when window size changes
self.data.bind('<Configure>', self.rewrap())
def rewrap(self):
self.data.config(wraplength = self.master.winfo_width())
frame01 = Wrap_example()
frame01.mainloop()
A few things of note: I tried using the lambda directly as shown in the linked answer, but it didn't work. If I remove the rewrap function and use self.data.bind('<Configure>', lambda e: self.data.config(wraplength=self.winfo_width()), it throws a generic Syntax error, always targeting the first character after that line, (the d in def if the function is left in, the f in frame01 if it's commented out). Leaving rewrap as-is doesn't throw an error, but it doesn't perform any other apparent function, either. Clicking 'Go' will always spawn data that wraps at the current window size, and never changes.
There are few issues:
frame Wrap_example does not fill all the horizontal space when window is resized
label self.data does not fill all the horizontal space inside frame Wrap_example when the frame is resized
self.rewrap() will be executed immediately when executing the line self.data.bind('<Configure>', self.rewrap())
To fix the above issues:
set relwidth=1 in self.place(...)
call self.columnconfigure(0, weight=1)
use self.data.bind('<Configure>', self.rewrap) (without () after rewrap) and add event argument in rewrap()
from tkinter import *
class Wrap_example(Frame):
def __init__(self):
Frame.__init__(self)
self.place(relx=0.5, anchor='n', relwidth=1) ### add relwidth=1
self.columnconfigure(0, weight=1) ### make column 0 use all available horizontal space
#Initalize list and variable that populates it
self.data_list = []
self.data = 0
#Button and function for creating a bunch of numbers to fill the space
self.button = Button(self, text = "Go", command = self.go)
self.button.grid()
def go(self):
for self.data in range(1, 20000, 100):
self.data_list.append(self.data)
#Label that holds the data, text = list, wraplength = current window width
self.data = Label(self, text = self.data_list, wraplength = self.master.winfo_width(), font = 'arial 30')
self.data.grid()
#Ostensibly sets the label to dynamically change wraplength to match new window size when window size changes
self.data.bind('<Configure>', self.rewrap) ### remove () after rewrap
def rewrap(self, event): ### add event argument
self.data.config(wraplength = self.master.winfo_width())
frame01 = Wrap_example()
frame01.mainloop()
I am aware that you cannot use different types of geometry managers within the same Tkinter window, such as .grid() and .pack(). I have a window that has been laid out using .grid() and I am now trying to add a status bar that would be snapped to the bottom of the window. The only method I have found online for this is to use .pack(side = BOTTOM), which will not work since the rest of the window uses .grid().
Is there a way that I can select the bottom of the window to place widgets from when using .grid()?
from tkinter import *
from tkinter.ttk import *
import tkinter as tk
class sample(Frame):
def __init__(self,master=None):
Frame.__init__(self, master)
self.status = StringVar()
self.status.set("Initializing")
statusbar = Label(root,textvariable = self.status,relief = SUNKEN, anchor = W)
statusbar.pack(side = BOTTOM, fill = X)
self.parent1 = Frame()
self.parent1.pack(side = TOP)
self.createwidgets()
def createwidgets(self):
Label(self.parent1,text = "Grid 1,1").grid(row = 1, column = 1)
Label(self.parent1,text = "Grid 1,2").grid(row = 1, column = 2)
Label(self.parent1,text = "Grid 2,1").grid(row = 2, column = 1)
Label(self.parent1,text = "Grid 2,2").grid(row = 2, column = 2)
if __name__ == '__main__':
root = Tk()
app = sample(master=root)
app.mainloop()
So using labels since I was kinda lazy to do other stuff, you can do frames to ensure that each section of your window can be packed/grid as required. Frames will be a useful tool for you to use when trying to arrange your widgets. Note that using a class can make things a little easier when deciding your parents. So imagine each frame is a parent and their children can be packed as required. So I would recommend drawing out your desired GUI and see how you will arrange them. Also if you want to add another frame within a frame simply do:
self.level2 = Frame(self.parent1)
You can check out additional settings in the docs
http://effbot.org/tkinterbook/frame.htm
PS: I am using a class hence the self, if you don't want to use classes then its okay to just change it to be without a class. Classes make it nicer to read though
Just give it a row argument that is larger than any other row. Then, give a weight to at least one of the rows before it.
Even better is to use frames to organize your code. Pack the scrollbar on the bottom and a frame above it. Then, use grid for everything inside the frame.
Example:
# layout of the root window
main = tk.Frame(root)
statusbar = tk.Label(root, text="this is the statusbar", anchor="w")
statusbar.pack(side="bottom", fill="x")
main.pack(side="top", fill="both", expand=True)
# layout of the main window
for row in range(1, 10):
label = tk.Label(main, text=f"R{row}")
label.grid(row=row, sticky="nsew")
main.grid_rowconfigure(row, weight=1)
...
I am creating a table in python GUI using the pack method where students can enter their name by "requesting" help.
Below is a modified and simplified version of my code.
import tkinter as tk
class App(object):
def __init__(self, master):
self._master = master
master.title = 'Table'
master.geometry('600x600')
frame = tk.Frame(master).pack()
button = tk.Button(frame, text="Ask for help",
command=self.request_help)
button.pack(side=tk.TOP)
# frame for hashtag
self._hashtagframe = tk.Frame(frame)
self._hashtagframe.pack(side=tk.LEFT)
# frame for Names
self._nameframe = tk.Frame(frame)
self._nameframe.pack(side=tk.LEFT)
# frame for buttons
self._timeframe = tk.Frame(frame).pack(side=tk.LEFT)
def request_help(self):
name = "BOB" # they enter some name
num = "number" # they are some number
namelabel=tk.Label(self._nameframe, text=name).pack(side=tk.TOP)
numlabel=tk.Label(self._hashtagframe, text=num).pack(side=tk.TOP)
student_timeframe = tk.Frame(self._timeframe).pack(side=tk.TOP)
redbutton = tk.Button(student_timeframe, command=blah1)
redbutton.pack(side=tk.LEFT)
greenbutton= tk.Button(student_timeframe, command=blah2)
greenbutton.pack(side=tk.LEFT)
When a student enters their name, in the button frame, a red and green button must appear. I am attempting to get this all in the same 'row' by creating a frame to put those 2 buttons in. However, when I run this code, the two buttons are veering way off to the side.
I have tried altering everything yet the text and 2 buttons keep veering over to the right. Does anyone know why this is?
You do
student_timeframe = tk.Frame(self._timeframe).pack(side=tk.TOP, anchor=tk.W, expand=True)
This stores the return value of pack() in student_timeframe, which is None.
Therefore, you don't actually pack your timelabel, redbutton and greenbutton in this frame, because you pass None as their parent, which makes it default to the root window.
Split up the line like
student_timeframe = tk.Frame(self._timeframe)
student_timeframe.pack(side=tk.TOP, anchor=tk.W, expand=True)
so that student_timeframe actually holds a reference to the Frame.
I apologize in advance if this is a stupid simple question, but i am really bad att python classes and can't seem to get it to work!
Here is my code:
from tkinter import *
a = Tk()
class toolsGUI():
def __init__(self, rootWin):
pass
def frame(self):
frame = Frame(rootWin)
frame.configure(bg = 'red')
frame.grid()
def button(self, binding, text):
btn = Button(rootWin, text=text)
btn.configure(bg = 'orange', fg = 'black')
btn.bind('<'+binding+'>')
btn.grid(row=1, sticky = N+S+E)
I simply want the button() or frame() to understand that rootWin is the same as in __init__, in this case rootWin should be variable a, thus placing the button in the Tk() window. After looking around, I understand that this is not the way to do it. Do anyone have another suggestion that might work?
You're pretty close. You are passing a to the toolsGUI initializer which is the right first step. You simply need to save this as an instance variable, then use the variable whenever you need to reference the root window:
def __init__(self, rootWin):
...
self.rootWin = rootWin
...
def frame(self):
frame = Frame(self.rootWin)
...
An alternative is to have toolsGUI inherit from Frame, in which case you can put all of the widgets in the frame instead of the root window. You then need the extra step of putting this frame inside the root window.
class toolsGUI(Frame):
def __init__(self, rootWin):
Frame.__init__(self, rootWin)
def frame(self):
frame = Frame(self)
...
a = Tk()
t = toolsGUI(a)
t.pack(fill="both", expand=True)
a.mainloop()
As a final bit of advice: don't user variables that are the same name as methods if you can avoid it. "frame" is a poor choice of function names. Instead, call it "create_frame" or something, otherwise it could be confused with class Frame and the local variable frame
I am trying to recreate the boardgame monopoly using python and tkinter. I know how to place a label on a canvas or a frame, but how should I do this command is being run from another function in the class? I tried it using some function within the class Board, but then the error rises that the label, canvas, etc. are not defined as this happens in __init__(self,parent). How can I solve these errors? Or should I take a different approach to this? Hope I made my problem clear.
import tkFileDialog
from random import randint
class Board(Frame):
def __init__(self,parent):
##create the board
frame = Frame(parent)
frame.pack()
Frame.__init__(self,parent)
frame2 = Frame(frame)
frame2.pack()
c=Canvas(frame2,width=480,height=480)
c.pack(expand=YES,fill=BOTH)
c.background=PhotoImage(file='Board.gif')
c.create_image(0,0,image=c.background,anchor='nw')
##Add player 1
player1=PhotoImage(file='plane.gif')
label_player1 = Label(c,image=player1)
label_player1.image=player1
label_player1.place(x=430,y=420)
##Add player 2
player2=PhotoImage(file='car.gif')
label_player2 = Label(c,image=player2)
label_player2.image=player2
label_player2.place(x=430,y=450)
button = Button(frame, text="Next turn", command=self.next_turn)
button.pack()
button = Button(frame, text="Roll the dice", command=self.roll)
button.pack()
def roll(self):
number=randint(2,12)
if b==0:
self.place_player_down()
return number
def place_player_down(self):
for i in range(number+1):
h=int(430-i*30)
while h>=0:
player2=PhotoImage(file='car.gif')
label_player2 = Label(c,image=player2)
label_player2.image=player2
label_player2.place(x=h,y=420)
root = Tk()
board = Board(root)
board.pack()
root.mainloop()
The approach is correct (wrap your Tkinter widgets in a class with the event handler functions as methods), but you forgot to set the widgets as attributes of the class using the reference to self:
class Board(Frame):
def __init__(self,parent):
# ...
self.c = Canvas(frame2,width=480,height=480)
self.c.pack(expand=YES,fill=BOTH)
# ...
def place_player_down(self):
# Use 'self.c', not just 'c'
I think you want to do something similar with the value number, but it that case I would send it as an argument to place_player_down:
def roll(self):
number=randint(2,12)
if b==0:
self.place_player_down(number)
return number # Keep in mind that this value is returned but not used anymore
def place_player_down(self, number):
# Use 'number'