[Tutor] if and things

[Ian Witham]

try this:

for a in range(10):
    r, g, b = pixel[1030*(y-a) + x]
    if g > r and g > b:
        box += 1

This is an example of "unpacking" a tuple into separate variables, r, g and
b.

On 7/19/07, elis aeris <hunter92383 at gmail.com> wrote:
>
> #  pixel[]  is a list of tuples:   (r,g,b)
> #  pixel[1030*(y-a) + x][0] = r
> #  pixel[1030*(y-a) + x][1] = g
> #  pixel[1030*(y-a) + x][2] = b
>
> for a in range(0, 10):
>     if    pixel[1030*(y-a) + x][1] > pixel[1030*(y-a) + x][0] and
> pixel[1030*(y-a) + x][1] > pixel[1030*(y-a) + x][2]:
>         box = box + 1
>
> print box
>
>
> i have never used double conditions before, is this correct?
>
> I want box++ when  the g is both bigger than r and b.
>
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>
> import time
>
> import ImageGrab  # Part of PIL
> from ctypes import *
>
> # Load up the Win32 APIs we need to use.
> class RECT(Structure):
>   _fields_ = [
>     ('left', c_ulong),
>     ('top', c_ulong),
>     ('right', c_ulong),
>     ('bottom', c_ulong)
>     ]
>
> # time.sleep(2)
>
> GetForegroundWindow = windll.user32.GetForegroundWindow
> GetWindowRect = windll.user32.GetWindowRect
>
> # Sleep for 2 seconds - click the window you want to grab.
> #time.sleep(2)
>
>
>
> # Grab the foreground window's screen rectangle.
> rect = RECT()
> foreground_window = GetForegroundWindow()
> GetWindowRect(foreground_window, byref(rect))
> image = ImageGrab.grab((rect.left, rect.top, rect.right, rect.bottom))
>
> # Save the screenshot as a BMP.
> time.sleep(2)
>
>
> image.save("c:\python_codes\screenshot.bmp")
>
> # Get the pixel 10 pixels along the top of the foreground window - this
> # will be a piece of the window border.
>
> # print time.time()
>
> start = time.time()
>
> pixels = image.getdata()
> for x in xrange(0, 500):
>   for y in xrange(0, 500):
>     rgb = pixels[500 * x + y]
>
> print pixels[1][0]
>
> print ( time.time() - start )
>
> # PIL returns colours as RGB values packed into a triple:
> #print "RGB(%d, %d, %d)" % (rgb[0], rgb[1], rgb[2])  # This prints RGB(0,
> 74, 216) on my XP machine
>
>
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