Problems with python3.6 on one system, but OK on another

Sat Jan 21 06:56:28 EST 2017

I build python3.6 on two systems. On one system everything is OK:
Python 3.6.0 (default, Jan 21 2017, 11:19:56) 
[GCC 4.9.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
But on another I get:
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Python 3.6.0 (default, Jan 21 2017, 12:20:38) 
[GCC 4.8.5] on linux
Type "help", "copyright", "credits" or "license" for more information.
Probably not a big problem, but just wondering what is happening here.
On both systems PYTHONHOME is not set and with the old version (3.4.5)
I did/do not get this message.
Another is that I used PYTHONSTARTUP to point to the following script:
 # startup script for python to enable saving of interpreter history and
 # enabling name completion
 # import needed modules
 import atexit
 import os
 import readline
 import rlcompleter
 # where is history saved
 historyPath = os.path.expanduser("~/.pyhistory")
 # handler for saving history
 def save_history(historyPath=historyPath):
 import readline
 try:
 readline.write_history_file(historyPath)
 except:
 pass
 # read history, if it exists
 if os.path.exists(historyPath):
 readline.set_history_length(10000)
 readline.read_history_file(historyPath)
 # register saving handler
 atexit.register(save_history)
 # enable completion
 readline.parse_and_bind('tab: complete')
 # cleanup
 del os, atexit, readline, rlcompleter, save_history, historyPath
This works with 3.4.5, but with 3.6 it gives:
Traceback (most recent call last):
 File "/etc/pythonstart", line 7, in <module>
 import readline
ModuleNotFoundError: No module named 'readline'
Probably not a big problem because I will mostly work with ipython3 at
the moment I get it working with 3.6, but just wondering.
By the way all other import (including rlcompleter) do work in 3.6.
-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof