Take screenshot without writing to disk

I want to have a python script that can take a screenshot without saving it directly to the disk immediately. Basically is there a module with a function that returns the raw bytes that I can then write into a file by myself manually?

import some_screenshot_module
raw_data = some_screenshot_module.return_raw_screenshot_bytes()
f = open('screenshot.png','wb')
f.write(raw_data)
f.close()

I have already checked out mss, pyscreenshot and PIL yet I could not find what I needed. I found a function that looked like what I was looking for, called frombytes. However after retrieving the bytes from the frombytes function and saving it into a file I couldn't view it not as a .BMP,.PNG,.JPG. Is there a function that returns the raw bytes that I can save into a file by myself or perhaps a module with a function like that?

Solution

As of MSS 3.1.2, with the commit dd5298, you can do that easily:

import mss
import mss.tools


with mss.mss() as sct:
    # Use the 1st monitor
    monitor = sct.monitors[1]

    # Grab the picture
    im = sct.grab(monitor)

    # Get the entire PNG raw bytes
    raw_bytes = mss.tools.to_png(im.rgb, im.size)

    # ...

The update is already available on PyPi.

Original answer

Using the MSS module, you can access to raw bytes:

import mss
import mss.tools


with mss.mss() as sct:
    # Use the 1st monitor
    monitor = sct.monitors[1]

    # Grab the picture
    im = sct.grab(monitor)

    # From now, you have access to different attributes like `rgb`
    # See https://python-mss.readthedocs.io/api.html#mss.tools.ScreenShot.rgb
    # `im.rgb` contains bytes of the screen shot in RGB _but_ you will have to
    # build the complete image because it does not set needed headers/structures
    # for PNG, JPEG or any picture format.
    # You can find the `to_png()` function that does this work for you,
    # you can create your own, just take inspiration here:
    # https://github.com/BoboTiG/python-mss/blob/master/mss/tools.py#L11

    # If you would use that function, it is dead simple:
    # args are (raw_data: bytes, (width, height): tuple, output: str)
    mss.tools.to_png(im.rgb, im.size, 'screenshot.png')

Another example using part of the screen: https://python-mss.readthedocs.io/examples.html#part-of-the-screen

Here is the documentation for more informations: https://python-mss.readthedocs.io/api.html