Change the width of a rectangle in tkinter's canvas widget
<p>I've tried several ways to change the width of the blue rectangle in this example code. Nothing seems to work. In the code, "a" represents a float variable between 1.00, and 0.00. That value is used to calculate "b," which is the desired width of the blue rectangle in pixels. I have some fairly complicated code that generates that value, and at least that works. In order for the code to work, the width of the blue rectangle must rely on "b." I've tried "Canvas.itemconfig()," and it didn't work.</p>

<pre><code>import tkinter
from tkinter import *

root = Tk()

root.maxsize(320,240)       # Sets max size of window
root.minsize(320,240)

canvas_height = 23
canvas_width = 315

w = Canvas(root, width=canvas_width, height=canvas_height)
w.pack()
w.create_rectangle(5, canvas_height, canvas_width, 2, fill="yellow")
w.create_rectangle(5, canvas_height, canvas_width, 2, fill="blue")

a = 1.0 # More complicated code creates this float between 0.00 and 1.00. It is a percentage of the desired 'blue rectangle' width
b = int(a * canvas_width)

root.mainloop() 
</code></pre>

<p>If anyone could help, I would greatly appreciate it!</p>

<p>P.s. I'm new to the Stackoverflow community, so please let me know if there's anything I can do to make my questions easier to answer.</p>