Create a gradient picture from python

gradient.py

from PIL import Image

#set the size of the new image
w = 500
h = 200

#start creating gradient
pixel_list = []
pixel_w = []

#colour at 0,0
start1 = (255,255,255)
s = list(start1)
pixel_list.append(start1)
print('Position zero:', pixel_list[0])

#colour at end
end1 = (174,15,15)
e = list(end1)

#in case you want to change the final colour you could use f to adjust otherwise just keep it at 1
f = 1

#transition per line
r = (s[0] - e[0])/w*f
g = (s[1] - e[1])/w*f
b = (s[2] - e[2])/w*f

t = ()

for j in range (0,w):
    t = pixel_list[j]

    #convert pixel tuple to a list and recalculate
    li = list(t)
    li[0] = int(max((li[0] - r*j),0))
    li[1] = int(max((li[1] - g*j),0))
    li[2] = int(max((li[2] - b*j),0))
    z = (li[0],li[1],li[2])
    final_t = tuple(z)
    #print('final_t:', final_t) if you want to show the list of pixel values
    pixel_list[j] = final_t
    for i in range (0,h):
        pixel_w = []
        pixel_w.append(final_t)
        pixel_list.extend(pixel_w)

l = len(pixel_list)

print('Pixel_list:', pixel_list, l)


#remove the last item
del pixel_list[l-1:]

print('Reprint length:', len(pixel_list))

im = Image.new('RGB', (w,h))
im.putdata(pixel_list)
im.show()