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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#     derived from this software without specific prior written consent.
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###

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

import textwrap

def expect(prompt, possibilities, recursed=False):
    """Prompt the user with prompt, allow them to choose from possibilities.

    If possibilities is empty, allow anything.
    """
    originalPrompt = prompt
    indent = ' ' * ((len(originalPrompt)%68) + 2)
    if recursed:
        print '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))
            prompt = textwrap.fill(prompt, subsequent_indent=indent)
    else:
        prompt = textwrap.fill(prompt)
    prompt = prompt.replace('/ ', '/')
    prompt = prompt.strip() + ' '
    s = raw_input(prompt)
    s = s.strip()
    if possibilities:
        if s in possibilities:
            return s
        else:
            return expect(originalPrompt, possibilities, recursed=True)
    else:
        return s.strip()

def expectWithDefault(prompt, possibilities, default):
    """Same as expect, except with a default."""
    indent = ' ' * ((len(prompt)%68) + 2)
    prompt = '%s [%s] (default: %s) ' % \
             (prompt.strip(), '/'.join(possibilities), default)
    if len(prompt) > 70:
        prompt = '%s [%s] (default: %s) ' % \
                 (prompt.strip(), ' / '.join(possibilities), default)
    prompt = textwrap.fill(prompt, subsequent_indent=indent)
    s = raw_input(prompt)
    s = s.strip()
    if s in possibilities:
        return s
    else:
        return default

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

def something(prompt):
    """Allow anything *except* nothing from the user."""
    s = expect(prompt, [])
    while not s:
        print 'Sorry, you must enter a value.'
        s = expect(prompt, [])
    return s

def yn(prompt):
    """Allow only 'y' or 'n' from the user."""
    return expect(prompt, ['y', 'n'])


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