scripts/release/io.py
author Mario Ferraro <fadinlight@gmail.com>
Sun, 15 Nov 2009 22:12:20 +0100
changeset 3093 d1be59b6b627
parent 1981 8cfb054b73b2
permissions -rw-r--r--
GMaps related JS changed to use new google namespace. Google is going to change permanently in the future the way to load its services, so better stay safe. Also this commit shows uses of the new melange.js module. Fixes Issue 634.

#!/usr/bin/python2.5
#
# Copyright 2009 the Melange authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import with_statement

"""User prompting and file access utilities."""

__authors__ = [
    # alphabetical order by last name, please
    '"David Anderson" <dave@natulte.net>',
    ]

import error
import log


class Error(error.Error):
  pass


class FileAccessError(Error):
  """An error occured while accessing a file."""
  pass


def getString(prompt):
  """Prompt for and return a string."""
  prompt += ' '
  log.stdout.write(prompt)
  log.stdout.flush()

  response = sys.stdin.readline()
  log.terminal_echo(prompt + response.strip())
  if not response:
    raise error.AbortedByUser('Aborted by ctrl+D')

  return response.strip()


def confirm(prompt, default=False):
  """Ask a yes/no question and return the answer.

  Will reprompt the user until one of "yes", "no", "y" or "n" is
  entered. The input is case insensitive.

  Args:
    prompt: The question to ask the user.
    default: The answer to return if the user just hits enter.

  Returns:
    True if the user answered affirmatively, False otherwise.
  """
  if default:
    question = prompt + ' [Yn]'
  else:
    question = prompt + ' [yN]'
  while True:
    answer = getString(question)
    if not answer:
      return default
    elif answer in ('y', 'yes'):
      return True
    elif answer in ('n', 'no'):
      return False
    else:
      log.error('Please answer yes or no.')


def getNumber(prompt):
  """Prompt for and return a number.

  Will reprompt the user until a number is entered.
  """
  while True:
    value_str = getString(prompt)
    try:
      return int(value_str)
    except ValueError:
      log.error('Please enter a number. You entered "%s".' % value_str)


def getChoice(intro, prompt, choices, done=None, suggest=None):
  """Prompt for and return a choice from a menu.

  Will reprompt the user until a valid menu entry is chosen.

  Args:
    intro: Text to print verbatim before the choice menu.
    prompt: The prompt to print right before accepting input.
    choices: The list of string choices to display.
    done: If not None, the list of indices of previously
      selected/completed choices.
    suggest: If not None, the index of the choice to highlight as
      the suggested choice.

  Returns:
    The index in the choices list of the selection the user made.
  """
  done = set(done or [])
  while True:
    print intro
    print
    for i, entry in enumerate(choices):
      done_text = ' (done)' if i in done else ''
      indent = '--> ' if i == suggest else '    '
      print '%s%2d. %s%s' % (indent, i+1, entry, done_text)
    print
    choice = getNumber(prompt)
    if 0 < choice <= len(choices):
      return choice-1
    log.error('%d is not a valid choice between %d and %d' %
              (choice, 1, len(choices)))
    print


def fileToLines(path):
  """Read a file and return it as a list of lines."""
  try:
    with file(path) as f:
      return f.read().split('\n')
  except (IOError, OSError), e:
    raise FileAccessError(str(e))


def linesToFile(path, lines):
  """Write a list of lines to a file."""
  try:
    with file(path, 'w') as f:
      f.write('\n'.join(lines))
  except (IOError, OSError), e:
    raise FileAccessError(str(e))