apt-get then doesn't bother to try installing sakura (according to the output you've provided).sudo apt-get install python-tk python2.7 sakura
Reading package lists... Done
Building dependency tree
Reading state information... Done
python-tk is already the newest version.
E: Couldn't find package python2.7
Later you try to run python2.7, though supposedly it doesn't exist because it wasn't installed.
Try a "which python" and then a "python --version". Let us know what it tells you...import _tkinter # If this fails your Python may not be configured for Tk