Tab自动完成功能和python cmd模块中子命令的简单实现？

Question

Is it possible to add tab autocomplete to subcommands in the python Cmd class in the cmd module? Say I am running my command loop, and I wanted to have a command called add , where I can then have a selection of animal names, like add horse , or add elephant . How can I tab autocomplete for any sub commands, if at all possible?

One thing I'm doing for the actual project I'm working on is using different classes for different modes. If you type whitelist , it runs another command loop in that class and is now in "whitelist" mode. You can then type exit to go back to the main command loop. That seems good for more heavyweight modes, but creating a whole new class the inherits Cmd seems a bit much for something as simple as adding different types of things like the example above. So, what is the best way to add simple (in terms of code) sub commands for the Cmd class that can be tab completed? Thanks.

Answer 1

The following works:

#!/usr/bin/env python


from __future__ import print_function


from cmd import Cmd
import readline  # noqa


class Zoo(Cmd):

    def __init__(self, animals):
        Cmd.__init__(self)

        self.animals = animals

    def do_add(self, animal):
        print("Animal {0:s} added".format(animal))

    def completedefault(self, text, line, begidx, endidx):
        tokens = line.split()
        if tokens[0].strip() == "add":
            return self.animal_matches(text)
        return []

    def animal_matches(self, text):
        matches = []
        n = len(text)
        for word in self.animals:
            if word[:n] == text:
                matches.append(word)
        return matches


animals = ["Bear", "Cat", "Cheetah", "Lion", "Zebra"]
zoo = Zoo(animals)
zoo.cmdloop()