def choose(msg, items, attr):  # pragma: no cover
    """ Command line helper to display a list of choices, asking the
        user to choose one of the options.
    """
    # Return the first item if there is only one choice
    if len(items) == 1:
        return items[0]
    # Print all choices to the command line
    print()
    for index, i in enumerate(items):
        name = attr(i) if callable(attr) else getattr(i, attr)
        print('  %s: %s' % (index, name))
    print()
    # Request choice from the user
    while True:
        try:
            inp = input('%s: ' % msg)
            if any(s in inp for s in (':', '::', '-')):
                idx = slice(*map(lambda x: int(x.strip()) if x.strip() else None, inp.split(':')))
                return items[idx]
            else:
                return items[int(inp)]

        except (ValueError, IndexError):
            pass
Command line helper to display a list of choices, asking the
        user to choose one of the options.