Limnoria/src/questions.py

#!/usr/bin/env python

###
# Copyright (c) 2002, Jeremiah Fincher
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#     this list of conditions, and the following disclaimer.
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#     contributors to this software may be used to endorse or promote products
#     derived from this software without specific prior written consent.
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# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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###

"""Handles interactive questions; useful for wizards and whatnot."""

__revision__ = "$Id$"

import sys
import textwrap
from getpass import getpass as getPass

import ansi
import utils

useBold = False

def output(s, unformatted=True):
    if unformatted:
        s = textwrap.fill(utils.normalizeWhitespace(s))
    print s
    print

def expect(prompt, possibilities, recursed=False, default=None,
           acceptEmpty=False):
    """Prompt the user with prompt, allow them to choose from possibilities.

    If possibilities is empty, allow anything.
    """
    prompt = utils.normalizeWhitespace(prompt)
    originalPrompt = prompt
    if recursed:
        output('Sorry, that response was not an option.')
    if possibilities:
        prompt = '%s [%s]' % (originalPrompt, '/'.join(possibilities))
        if len(prompt) > 70:
            prompt = '%s [%s]' % (originalPrompt, '/ '.join(possibilities))
    if default is not None:
        prompt = '%s (default: %s)' % (prompt, default)
    prompt = textwrap.fill(prompt)
    prompt = prompt.replace('/ ', '/')
    prompt = prompt.strip() + ' '
    if useBold:
        sys.stdout.write(ansi.BOLD)
    s = raw_input(prompt)
    if useBold:
        print ansi.RESET
    s = s.strip()
    print
    if possibilities:
        if s in possibilities:
            return s
        elif not s and default is not None:
            return default
        elif not s and acceptEmpty:
            return s
        else:
            return expect(originalPrompt, possibilities, recursed=True,
                          default=default)
    else:
        if not s and default is not None:
            return default
        return s.strip()

def anything(prompt):
    """Allow anything from the user."""
    return expect(prompt, [])

def something(prompt, default=None):
    """Allow anything *except* nothing from the user."""
    s = expect(prompt, [], default=default)
    while not s:
        output('Sorry, you must enter a value.')
        s = expect(prompt, [], default=default)
    return s

def yn(prompt, default=None):
    """Allow only 'y' or 'n' from the user."""
    if default is not None:
        if default:
            default = 'y'
        else:
            default = 'n'
    s = expect(prompt, ['y', 'n'], default=default)
    if s is 'y':
        return True
    else:
        return False

def getpass(prompt='Enter password: ', secondPrompt='Re-enter password: '):
    """Prompt the user for a password."""
    password = ''
    secondPassword = ' ' # Note that this should be different than password.
    assert prompt
    if not prompt[-1].isspace():
        prompt += ' '
    while True:
        if useBold:
            sys.stdout.write(ansi.BOLD)
        password = getPass(prompt)
        secondPassword = getPass(secondPrompt)
        if useBold:
            print ansi.RESET
        if password != secondPassword:
            output('Passwords don\'t match.')
        else:
            break
    return password


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