You return four variables s1,s2,s3,s4 and receive them using a single variable obj. This is what is called a tuple, obj is associated with 4 values, the values of s1,s2,s3,s4. So, use index as you use in a list to get the value you want, in order.

Copyobj=list_benefits()
print obj[0] + " is a benefit of functions!"
print obj[1] + " is a benefit of functions!"
print obj[2] + " is a benefit of functions!"
print obj[3] + " is a benefit of functions!"

It's not clear from your description whether camera1[2] is a flat list of consecutive R, G, B, A values, or whether it's a list of RGBA tuples. So I'll show you how to read both options. ;)

Your main problem is that your data doesn't contain width and height information, so we need to supply that info, somehow. One way to do that would be to read the data into a 3D Numpy array of the correct shape. But we can also do it directly in PIL by using the appropriate Image methods.

For my demonstrations I use Python loops to create some simple RGBA data.

This script creates a list of RGBA tuples.

from PIL import Image

maxval = 255
width, height = 400, 300

# Display size info
size = width * height
fmt = 'Width: {}, Height: {}, Pixels: {}, Bytes: {}'
print(fmt.format(width, height, size, size * 4))

# Make a 2D gradient that starts at black in the top left corner,
# with red & green increasing horizontally, blue increasing vertically.
# This would be much faster using Numpy instead of Python loops.
pixels = []
# Make all pixels fully opaque
alpha = maxval
for y in range(height):
    blu = maxval * y // height
    for x in range(width):
        red = gre = maxval * x // width
        # Make a single RGBA pixel as a tuple
        pix = red, gre, blu, alpha
        # And save it
        pixels.append(pix)

# Show that the size of `pixels` is correct and show the first few pixels
print('Size:', len(pixels))
print(pixels[:8])

# Make a new image object. All pixels are set to black. 
img = Image.new('RGBA', (width, height))
# Copy the pixel data to the Image
img.putdata(pixels)
img.show()
img.save('test1.png') 

output

Width: 400, Height: 300, Pixels: 120000, Bytes: 480000
Size: 120000
[(0, 0, 0, 255), (0, 0, 0, 255), (1, 1, 0, 255), (1, 1, 0, 255), (2, 2, 0, 255), (3, 3, 0, 255), (3, 3, 0, 255), (4, 4, 0, 255)]

test1.png

This script creates a flat list of R, G, B, A values. It uses a Python 3 bytes object, so it won't work properly on Python 2.

from PIL import Image

maxval = 255
width, height = 400, 300

# Display size info
size = width * height
fmt = 'Width: {}, Height: {}, Pixels: {}, Bytes: {}'
print(fmt.format(width, height, size, size * 4))

# Make a 2D gradient that starts at black in the top left corner,
# with red & green increasing horizontally, blue increasing vertically.
# This would be much faster using Numpy instead of Python loops.
rgba = []
# Make all pixels fully opaque
alpha = maxval
for y in range(height):
    blu = maxval * y // height
    for x in range(width):
        red = gre = maxval * x // width
        # Make a single RGBA pixel as a tuple
        pix = red, gre, blu, alpha
        # And save each of red, gre, blu, alpha to rgba. 
        # By using `.extend` we create a flat list
        rgba.extend(pix)

# Show that the size of `rgba` is correct and show the first few values.
print('Size:', len(rgba))
print(rgba[:32])

# Convert the rgba list to bytes.
rgba = bytes(rgba)
# Make a new image object from the bytes
img = Image.frombytes('RGBA', (width, height), rgba)
img.show()
img.save('test2.png')

output

Width: 400, Height: 300, Pixels: 120000, Bytes: 480000
Size: 480000
[0, 0, 0, 255, 0, 0, 0, 255, 1, 1, 0, 255, 1, 1, 0, 255, 2, 2, 0, 255, 3, 3, 0, 255, 3, 3, 0, 255, 4, 4, 0, 255]

The file 'test2.png' is identical to 'test1.png'.

have created a list in my code..

No you haven't you've create a tuple. Use a list instead:

lst = [x,y]

lst.append('red')