Tab completion in Python's raw_input()

Question

i know i can do this to get the effect of tab completion in python sure.

import readline COMMANDS = ['extra', 'extension', 'stuff', 'errors',             'email', 'foobar', 'foo']  def complete(text, state):     for cmd in COMMANDS:         if cmd.startswith(text):             if not state:                 return cmd             else:                 state -= 1  readline.parse_and_bind("tab: complete") readline.set_completer(complete) raw_input('Enter section name: ') 

I am now interested in doing tab completion with directories. (/home/user/doc >tab)

How would i go about doing such a task?

Answer 1

Here is a quick example of how to perform incremental completion of file system paths. I've modified your example, organizing it into a class where methods named complete_[name] indicate top-level commands.

I've switched the completion function to use the internal readline buffer to determine the state of the overall completion, which makes the state logic a bit simpler. The path completion is in the _complete_path(path) method, and I've hooked up the extra command to perform path completions on its arguments.

I'm sure the code could be further simplified but it should provide you a decent starting point:

import os import re import readline  COMMANDS = ['extra', 'extension', 'stuff', 'errors',             'email', 'foobar', 'foo'] RE_SPACE = re.compile('.*\s+$', re.M)  class Completer(object):      def _listdir(self, root):         "List directory 'root' appending the path separator to subdirs."         res = []         for name in os.listdir(root):             path = os.path.join(root, name)             if os.path.isdir(path):                 name += os.sep             res.append(name)         return res      def _complete_path(self, path=None):         "Perform completion of filesystem path."         if not path:             return self._listdir('.')         dirname, rest = os.path.split(path)         tmp = dirname if dirname else '.'         res = [os.path.join(dirname, p)                 for p in self._listdir(tmp) if p.startswith(rest)]         # more than one match, or single match which does not exist (typo)         if len(res) > 1 or not os.path.exists(path):             return res         # resolved to a single directory, so return list of files below it         if os.path.isdir(path):             return [os.path.join(path, p) for p in self._listdir(path)]         # exact file match terminates this completion         return [path + ' ']      def complete_extra(self, args):         "Completions for the 'extra' command."         if not args:             return self._complete_path('.')         # treat the last arg as a path and complete it         return self._complete_path(args[-1])      def complete(self, text, state):         "Generic readline completion entry point."         buffer = readline.get_line_buffer()         line = readline.get_line_buffer().split()         # show all commands         if not line:             return [c + ' ' for c in COMMANDS][state]         # account for last argument ending in a space         if RE_SPACE.match(buffer):             line.append('')         # resolve command to the implementation function         cmd = line[0].strip()         if cmd in COMMANDS:             impl = getattr(self, 'complete_%s' % cmd)             args = line[1:]             if args:                 return (impl(args) + [None])[state]             return [cmd + ' '][state]         results = [c + ' ' for c in COMMANDS if c.startswith(cmd)] + [None]         return results[state]  comp = Completer() # we want to treat '/' as part of a word, so override the delimiters readline.set_completer_delims(' \t\n;') readline.parse_and_bind("tab: complete") readline.set_completer(comp.complete) raw_input('Enter section name: ') 

Usage:

% python complete.py  Enter section name: ext<tab> extension extra Enter section name: extra foo<tab> foo.py foo.txt foo/ Enter section name: extra foo/<tab> foo/bar.txt foo/baz.txt Enter section name: extra foo/bar.txt 

Update It will complete paths from the root if the user types /:

% python complete.py Enter section name: extra /Use<tab> /Users/.localized  /Users/Shared/  /Users/user1 /Users/user2 Enter section name: extra /Users/use<tab> /Users/user1  /Users/user2 

Answer 2

This is enough to enable built in directory tab completion with raw_input():

import readline readline.parse_and_bind("tab: complete")