[root@centos7 ~]# cat tab.py
#!/usr/bin/python3.6
# python startup file
import sys
import readline
import rlcompleter
import atexit
import os
# tab completion 
readline.parse_and_bind('tab:complete')
# history file 
histfile = os.path.join(os.environ['HOME'],'.pythonhistory')
try:
    readline.read_history_file(histfile)
except IOError:
    pass
atexit.register(readline.write_history_file,histfile)
del os, histfile, readline,rlcompleter