There are a lot of things in PythonSuch a similar problem .
Google again, only to find the answer-for idle add a clear screen extension clearwindow on it (in/ httpbugs.python.org/issue61 +can see the description of this extension).
below I say install the method that uses. Download Firstclearwindow.py(click to download directly, can not download the right-click Save, the format is the end of the Py), the file is placed in the Python x\lib\idlelib directory (X for your Python version), Then find config-extensions.def this file (the idle extension profile) in this directory and open it in Notepad (to prevent errors, you can copy a backup before you open it). Well, after opening it may look dense, if you can, suggest you better use likeSublime textor VIM supports a highlighted editor to open it.
after opening the config-extensions.def, add these sentences at the end of the sentence:
[ClearWindow]
enable=1
enable_editor=0
enable_shell=1
[Clearwindow_cfgbindings]
clear-window=<control-key-l>
then save the exit and you're ready.
Open Python's idle and see if options are more than one option clear shell window ctrl+l
If this is the case, then it proves that you have successfully installed, after the screen to clear the direct ctrl+l can be
Python shell (IDLE) Clear screen settings