How to make a python, command-line program autocomplete arbitrary things NOT interpreter

Question

I am aware of how to setup autocompletion of python objects in the python interpreter (on unix).

• Google shows many hits for explanations on how to do this.
• Unfortunately, there are so many references to that it is difficult to find what I need to do, which is slightly different.

I need to know how to enable, tab/auto completion of arbitrary items in a command-line program written in python.

My specific use case is a command-line python program that needs to send emails. I want to be able to autocomplete email addresses (I have the addresses on disk) when the user types part of it (and optionally presses the TAB key).

I do not need it to work on windows or mac, just linux.

Answer 1

Use Python's readline bindings. For example,

import readline  def completer(text, state):     options = [i for i in commands if i.startswith(text)]     if state < len(options):         return options[state]     else:         return None  readline.parse_and_bind("tab: complete") readline.set_completer(completer) 

The official module docs aren't much more detailed, see the readline docs for more info.

Answer 2

Follow the cmd documentation and you'll be fine

import cmd  addresses = [     '[email protected]',     '[email protected]',     '[email protected]', ]  class MyCmd(cmd.Cmd):     def do_send(self, line):         pass      def complete_send(self, text, line, start_index, end_index):         if text:             return [                 address for address in addresses                 if address.startswith(text)             ]         else:             return addresses   if __name__ == '__main__':     my_cmd = MyCmd()     my_cmd.cmdloop() 

Output for tab -> tab -> send -> tab -> tab -> f -> tab

(Cmd) help  send (Cmd) send [email protected]            [email protected]         [email protected] (Cmd) send [email protected] (Cmd)