I'm trying to implement my own version of the 'cd' command that presents the user with a list of hard-coded directories to choose from, and the user has to enter a number corresponding to an entry in the list. The program, named my_cd.py for now, should then effectively 'cd' the user to the chosen directory. Example of how this should work: /some/directory $ my_cd.py 1) ~ 2) /bin/ 3) /usr Enter menu selection, or q to quit: 2 /bin $ Currently, I'm trying to 'cd' using os.chdir('dir'). However, this doesn't work, probably because my_cd.py is kicked off in its own child process. I tried wrapping the call to my_cd.py in a sourced bash script named my_cd.sh: #! /bin/bash function my_cd() { /path/to/my_cd.py } /some/directory $ . my_cd.sh $ my_cd ... shows list of dirs, but doesn't 'cd' in the interactive shell Any ideas on how I can get this to work? Is it possible to change my interactive shell's current directory from a python script?