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 = [x in addrs where x.startswith(text)]
    if state < options.length:
        return options[state]
    else
        return None
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)

Answer 3

Here is a full-working version of the code that was very supplied by ephemient here (thank you).

import readline

addrs = ['[email protected]', '[email protected]', '[email protected]']

def completer(text, state):
    options = [x for x in addrs if x.startswith(text)]
    try:
        return options[state]
    except IndexError:
        return None

readline.set_completer(completer)
readline.parse_and_bind("tab: complete")

while 1:
    a = raw_input("> ")
    print "You entered", a

Answer 4

See here for a version that matches any part of the string, not just the beginning, and is case insensitive.