title: What is the difference between these two ways of passing arguments?
body: <p>In Python, these two examples do the same thing:</p>
  
  <pre><code>from tkinter import Label
  widget = Label(None, text='Hello')
  widget.pack()
  widget.mainloop()
  
  from tkinter import Label
  widget = Label(None,'Hello')
  widget.pack()
  widget.mainloop()
  </code></pre>
  
  <p>I think <code>Label</code> is a class, and when I try to create an instance of that class, I always do the same thing as in the last code example. I feel strange about the meaning of <code>text='Hello'</code>. Could anyone please tell me about that?</p>