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pythontkinterlambdaparameters

Lambda parameter in for loop takes a <ButtonPress event state=Mod num=1 x= y=> value

Context Menu should show filter variables dynamically and execute a lambda function with parameters defined inside the callback.

import tkinter as tk

...

def get_text():

...
    for i in range(len(obj_list)):
        guidelines = tk.Label(window, text="{0} : {1} ore".format(obj_list[i].name,obj_list[i].nr_ore), fg="blue", cursor="hand2")
        guidelines.grid(row=7+i, column=0, sticky='nsew')
        guidelines.bind("<Button-1>", lambda i=i: show_guide_lines(i))
...
def show_guide_lines(i):
    window_guide_lines = tk.Toplevel(window)
    window_guide_lines.title('Guide Lines')
    window_guide_lines.geometry('400x200')
    print(i)
    guide_line_text = str(i)
    tk.Label(window_guide_lines, text=guide_line_text).pack()

    window_guide_lines.tkraise()
    window_guide_lines.focus_force()
...
window=tk.Tk()
window.title('Calculare numar de ore')
window.eval('tk::PlaceWindow . center')

frame=tk.Frame(window, width=500, height=10)
frame.grid(row=0,column=0)

...

window.mainloop()

The problem is that the i parameter in the show_guide_lines function takes the value when he should be a number and i don't know why. Thank you in advance enter image description here

Solution

  • As the first argument of the callback of an event binding is the Event object, so the lambda definition should be as below:

    guidelines.bind("<Button-1>", lambda e, i=i: show_guide_lines(i))