Change how Python Cmd Module handles autocompletion

Question

I have a Cmd console set up to auto-complete card names for a Magic: the Gathering collection management system.

It uses the text parameter to query the database for car

Answer 1

It shouldn't need to be overly complicated. Something like the following:

import cmd

completions = [
    'Mage Slayer (Alara Reborn)',
    'Magefire Wings (Alara Reborn)',
    'Sages of the Anima (Alara Reborn)',
    'Sanctum Plowbeast (Alara Reborn)',
    'Sangrite Backlash (Alara Reborn)',
    'Sanity Gnawers (Alara Reborn)',
    'Sen Triplets (Alara Reborn)'
]

class mycmd(cmd.Cmd):
    def __init__(self):
        cmd.Cmd.__init__(self)

    def do_quit(self, s):
        return True

    def do_add(self, s):
        pass

    def complete_add(self, text, line, begidx, endidx):
        mline = line.partition(' ')[2]
        offs = len(mline) - len(text)
        return [s[offs:] for s in completions if s.startswith(mline)]

if __name__ == '__main__':
    mycmd().cmdloop()

Answer 2

You could do readline.set_completer_delims('').

However, your complete_* functions won't be called anymore; you will have to override Cmd.complete or Cmd.completenames. Look at the sourcecode of the cmd module for details.

Answer 3

I did override of the cmdloop function, and it was pretty straightforward. I didn't have to change anything else. Just copy the cmdloop function from the module (find code by doing import cmd, cmd.__file__), and add the two lines for changing delimiters:

    try:
       import readline
       self.old_completer = readline.get_completer()
       readline.set_completer(self.complete)
       readline.parse_and_bind(self.completekey+": complete")
       # do not use - as delimiter
       old_delims = readline.get_completer_delims() # <-
       readline.set_completer_delims(old_delims.replace('-', '')) # <-
    except ImportError:
        pass

That did it for me. In your case you may want to remove whichever delimiter is causing the issues.