Take a screenshot via a Python script on Linux

This works without having to use scrot or ImageMagick.

import gtk.gdk

w = gtk.gdk.get_default_root_window()
sz = w.get_size()
print "The size of the window is %d x %d" % sz
pb = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB,False,8,sz[0],sz[1])
pb = pb.get_from_drawable(w,w.get_colormap(),0,0,0,0,sz[0],sz[1])
if (pb != None):
    pb.save("screenshot.png","png")
    print "Screenshot saved to screenshot.png."
else:
    print "Unable to get the screenshot."

Borrowed from http://ubuntuforums.org/showpost.php?p=2681009&postcount=5

This one works on X11, and perhaps on Windows too (someone, please check). Needs PyQt4:

import sys
from PyQt4.QtGui import QPixmap, QApplication
app = QApplication(sys.argv)
QPixmap.grabWindow(QApplication.desktop().winId()).save('test.png', 'png')

import ImageGrab
img = ImageGrab.grab()
img.save('test.jpg','JPEG')

this requires Python Imaging Library

You can use this

import os
os.system("import -window root screen_shot.png")

for ubuntu this work for me, you can take a screenshot of select window with this:

import gi
gi.require_version('Gtk', '3.0')
gi.require_version('Gdk', '3.0')

from gi.repository import Gdk
from gi.repository import GdkPixbuf
import numpy as np
from Xlib.display import Display

#define the window name
window_name = 'Spotify'

#define xid of your select 'window'
def locate_window(stack,window):
    disp = Display()
    NET_WM_NAME = disp.intern_atom('_NET_WM_NAME')
    WM_NAME = disp.intern_atom('WM_NAME') 
    name= []
    for i, w in enumerate(stack):
        win_id =w.get_xid()
        window_obj = disp.create_resource_object('window', win_id)
        for atom in (NET_WM_NAME, WM_NAME):
            window_name=window_obj.get_full_property(atom, 0)
            name.append(window_name.value)
    for l in range(len(stack)):
        if(name[2*l]==window):
            return stack[l]

window = Gdk.get_default_root_window()
screen = window.get_screen()
stack = screen.get_window_stack()
myselectwindow = locate_window(stack,window_name)
img_pixbuf = Gdk.pixbuf_get_from_window(myselectwindow,*myselectwindow.get_geometry()) 

to transform pixbuf into array

def pixbuf_to_array(p):
    w,h,c,r=(p.get_width(), p.get_height(), p.get_n_channels(), p.get_rowstride())
    assert p.get_colorspace() == GdkPixbuf.Colorspace.RGB
    assert p.get_bits_per_sample() == 8
    if  p.get_has_alpha():
        assert c == 4
    else:
        assert c == 3
    assert r >= w * c
    a=np.frombuffer(p.get_pixels(),dtype=np.uint8)
    if a.shape[0] == w*c*h:
        return a.reshape( (h, w, c) )
    else:
        b=np.zeros((h,w*c),'uint8')
        for j in range(h):
            b[j,:]=a[r*j:r*j+w*c]
        return b.reshape( (h, w, c) )

beauty_print = pixbuf_to_array(img_pixbuf)

Try it:

#!/usr/bin/python

import gtk.gdk
import time
import random
import socket
import fcntl
import struct
import getpass
import os
import paramiko     

while 1:
    # generate a random time between 120 and 300 sec
    random_time = random.randrange(20,25)
    # wait between 120 and 300 seconds (or between 2 and 5 minutes) 

    print "Next picture in: %.2f minutes" % (float(random_time) / 60)

    time.sleep(random_time)
    w = gtk.gdk.get_default_root_window()   
    sz = w.get_size()
    print "The size of the window is %d x %d" % sz
    pb = gtk.gdk.Pixbuf(gtk.gdk.COLORSPACE_RGB,False,8,sz[0],sz[1])
    pb = pb.get_from_drawable(w,w.get_colormap(),0,0,0,0,sz[0],sz[1])
    ts = time.asctime( time.localtime(time.time()) )
    date = time.strftime("%d-%m-%Y")
    timer = time.strftime("%I:%M:%S%p")
    filename = timer
    filename += ".png"

    if (pb != None):
        username = getpass.getuser() #Get username
        newpath = r'screenshots/'+username+'/'+date #screenshot save path
        if not os.path.exists(newpath): os.makedirs(newpath)
        saveas = os.path.join(newpath,filename)
        print saveas
        pb.save(saveas,"png")
    else:
        print "Unable to get the screenshot."