python, tkinter: text is pasted twice from clipboard - why?

Question

I implemented a standard copy & paste functionality for a text editor that I write, but it seems i did not understand the behaviour of the insert-method of the scrolledtext widget in tkinter correctly: My code does not behave the way I would expect.

Here as minimal example. It's a window with scrolledtext widget and a button that loads a sample file "Test.txt" to the text widget and an end button. the copy & paste functionality is implemented over the shortcuts ctrl-c, ctrl-v. At pasting, the code inserts the content of the clipboard twice instaed of one and I have absolutely NO IDEA why. Can anyone show me what i did wrong? Thanks in advance!

import tkinter, tkinter.scrolledtext

def ende():
    main.destroy()

def loadSampleFile():
    d=open("Test.txt")
    z=d.readline()
    while z:
    t.insert("end",z)
    z=d.readline()
    d.close()

def paste(event_obj):
    text2paste=t.selection_get(selection='CLIPBOARD')
    print(t.clipboard_get())
    t.insert('insert',text2paste)

def copy2clipboard(event_obj):
    text2copy=t.get(tkinter.SEL_FIRST,tkinter.SEL_LAST)
    t.clipboard_clear()
    t.clipboard_append(text2copy)

main=tkinter.Tk()
t=tkinter.scrolledtext.ScrolledText(main, width=40, height=1)
t.pack()
t.bind('<Control-c>',copy2clipboard)
t.bind('<Control-v>',paste)

bshow=tkinter.Button(main, text="Show File", command=loadSampleFile)
bshow.pack()

bende=tkinter.Button(main, text="end", command=ende)
bende.pack()


main.mainloop()

Answer 1

It's because ctrl-c and ctrl-v is already implemented.

So when you do ctrl-v, it pastes once for already implemented one and once for your method. Just remove binding overall or if you want to do something on ctrl-v, then remove insert in your method.