Howto Do Python Command-Line Autocompletion But Not Only at the Beginning of a String

Howto do python command-line autocompletion but NOT only at the beginning of a string

I'm not sure I understand the problem. You could use readline.clear_history and readline.add_history to set up the completable strings you want, then control-r to search backword in the history (just as if you were at a shell prompt). For example:

#!/usr/bin/env python

import readline

readline.clear_history()
readline.add_history('foo')
readline.add_history('bar')

while 1:
    print raw_input('> ')

Alternatively, you could write your own completer version and bind the appropriate key to it. This version uses caching in case your match list is huge:

#!/usr/bin/env python

import readline

values = ['Paul Eden <paul@domain.com>', 
          'Eden Jones <ejones@domain.com>', 
          'Somebody Else <somebody@domain.com>']
completions = {}

def completer(text, state):
    try:
        matches = completions[text]
    except KeyError:
        matches = [value for value in values
                   if text.upper() in value.upper()]
        completions[text] = matches
    try:
        return matches[state]
    except IndexError:
        return None

readline.set_completer(completer)
readline.parse_and_bind('tab: menu-complete')

while 1:
    a = raw_input('> ')
    print 'said:', a

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

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.

TAB autocomplete python CLI

That is a feature of the shell, not of the Python script being called. See this question on SO for more info on shell completion. In particular, you're looking for programmable completion.

Autocompletion in Python shell only when it makes sense

I found ptpython ptpython, which can be easily embedded in a shell.
Edit: that project has too many features for me. I can use ipython instead of the python shell

Cmd module : having completion on the first word

The answer is actually simple : Cmd.completenames. More info here. A similar question here.

Command-line autocompletion for python -m module

As said in the comment section, you need to extend the bash-completion tool. Then, you'll create a script which handles the cases you need (ie: when the last argument was -m).

This little sample below shows a start for your custom completion script. Let's name it python_completion.sh.

_python_target() {
    local cur prev opts

    # Retrieving the current typed argument
    cur="${COMP_WORDS[COMP_CWORD]}"

    # Retrieving the previous typed argument ("-m" for example)
    prev="${COMP_WORDS[COMP_CWORD-1]}"

    # Preparing an array to store available list for completions
    # COMREPLY will be checked to suggest the list
    COMPREPLY=()

    # Here, we'll only handle the case of "-m"
    # Hence, the classic autocompletion is disabled
    # (ie COMREPLY stays an empty array)
    if [[ "$prev" != "-m" ]]
    then
        return 0
    fi

    # Retrieving paths and converts their separators into dots
    # (if packages doesn't exist, same thing, empty array)
    if [[ ! -e "./package" ]]
    then
       return 0
    fi

    # Otherwise, we retrieve first the paths starting with "./package"
    # and converts their separators into dots
    opts="$(find ./package -type d | sed -e 's+/+.+g' -e 's/^\.//' | head)"

    # We store the whole list by invoking "compgen" and filling
    # COMREPLY with its output content.
    COMPREPLY=($(compgen -W "$opts" -- "$cur"))

}

complete -F _python_target python

(Warning. This script has a flaw, it won't work with filenames containing spaces). To test it, run it in the current environnement:

. ./python_completion.sh

And test it:

python -m packag[TAB]

Here is a tutorial to continue in this way.

How to write code to autocomplete words and sentences?

(I'm aware this isn't exactly what you're asking for, but) If you're happy with the auto-completion/suggestions appearing on TAB (as used in many shells), then you can quickly get up and running using the readline module.

Here's a quick example based on Doug Hellmann's PyMOTW writeup on readline.

import readline

class MyCompleter(object):  # Custom completer

    def __init__(self, options):
        self.options = sorted(options)

    def complete(self, text, state):
        if state == 0:  # on first trigger, build possible matches
            if text:  # cache matches (entries that start with entered text)
                self.matches = [s for s in self.options 
                                    if s and s.startswith(text)]
            else:  # no text entered, all matches possible
                self.matches = self.options[:]

        # return match indexed by state
        try: 
            return self.matches[state]
        except IndexError:
            return None

completer = MyCompleter(["hello", "hi", "how are you", "goodbye", "great"])
readline.set_completer(completer.complete)
readline.parse_and_bind('tab: complete')

input = raw_input("Input: ")
print "You entered", input

This results in the following behaviour (<TAB> representing a the tab key being pressed):

Input: <TAB><TAB>
goodbye      great        hello        hi           how are you

Input: h<TAB><TAB>
hello        hi           how are you

Input: ho<TAB>ow are you

In the last line (HOTAB entered), there is only one possible match and the whole sentence "how are you" is auto completed.

Check out the linked articles for more information on readline.

---

"And better yet would be if it would complete words not only from the beginning ... completion from arbitrary part of the string."

This can be achieved by simply modifying the match criteria in the completer function, ie. from:

self.matches = [s for s in self.options 
                   if s and s.startswith(text)]

to something like:

self.matches = [s for s in self.options 
                   if text in s]

This will give you the following behaviour:

Input: <TAB><TAB>
goodbye      great        hello        hi           how are you

Input: o<TAB><TAB>
goodbye      hello        how are you

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Updates: using the history buffer (as mentioned in comments)

A simple way to create a pseudo-menu for scrolling/searching is to load the keywords into the history buffer. You will then be able to scroll through the entries using the up/down arrow keys as well as use Ctrl+R to perform a reverse-search.

To try this out, make the following changes:

keywords = ["hello", "hi", "how are you", "goodbye", "great"]
completer = MyCompleter(keywords)
readline.set_completer(completer.complete)
readline.parse_and_bind('tab: complete')
for kw in keywords:
    readline.add_history(kw)

input = raw_input("Input: ")
print "You entered", input

When you run the script, try typing Ctrl+r followed by a. That will return the first match that contains "a". Enter Ctrl+r again for the next match. To select an entry, press ENTER.

Also try using the UP/DOWN keys to scroll through the keywords.

Change how Python Cmd Module handles autocompletion

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()

Tab Completion in Python Command Line Interface - how to catch Tab events

For that you use the readline module.

Simplest code I can think:

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: ')

Example usage:

Enter section name: <tab>
email      errors     extension  extra      foo        foobar    stuff
Enter section name: e<tab>
email      errors     extension  extra      
Enter section name: ext<tab>
extension  extra      

Besides completion, readline provides you with:

• Line editing
• Keybinding configuration (emacs and vi modes included)
• History (up arrow to recall previous values)
• History searching, saving and loading

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