Please be careful, when you’re coding

Today I continue to develop the GUI Program Bark, and have added a new page --Verify_Page, but when I processed the App.py, and switched to other pages there always show the content of Verify_Page, so terrible, I took so much time to find where have wrong, finally, I found a bug in create tk.Label and Button, I was lost the parameter of ‘self’ point to tk.Tk(), just like the root, the root=tk.Tk(), so the result is they showing on App Window still when I switched a page.
If I can be careful when I am coding, this trouble won’t appear, I won’t spend so much time to locate error, then in the end I want to say again: please be careful and patient.