在python中使用Tkinter set（）属性和网格布局

Question

I've tried a number of different ways to use the Slider set() in tkinter with the grid layout and I cannot get it to recognize the attribute.

Here's a functional version not using set():

master = Tk()
master.title("This is a title")

Scale(master, from_=0, to=100, label='Brightness').grid(row=0, sticky=W)

master.mainloop()

This works as would be expected. But if I change to:

Scale(master, from_=0, to=100, label='Brightness').set(50).grid(row=0, sticky=W)

I receive: AttributeError: 'NoneType' object has no attribute 'grid'

If I try to assign the scale to a variable with set() and then use that variable with .grid(row=0, sticky=W) I receive the same thing.

What is it that I am missing here? I looked through the docs, but it seems there's little on grid() as compared to pack() .

Answer 1

This should work.

scl = Scale(master, from_=0, to=100, label='Brightness')
scl.set(50)
scl.grid(row=0, sticky=W)

set method returns None. You are getting None type error because of that. As you can see from above code, you should first assign to a variable then use methods on that variable.