Return integer value read from keyboard

    Parameters
    ----------
    prompt : str
        Prompt string.
    default : integer, str or None
        Default value.
    minval :  integer or None
        Mininum allowed value.
    maxval :  integer or None
        Maximum allowed value.
    allowed_single_chars : str
        String containing allowed valid characters.
    question_mark : bool
        If True, display question mark after prompt.

    Returns
    -------
    result : integer
        Read value.

def readi(prompt, default=None, minval=None, maxval=None,
          allowed_single_chars=None, question_mark=True):
    """Return integer value read from keyboard

    Parameters
    ----------
    prompt : str
        Prompt string.
    default : integer, str or None
        Default value.
    minval :  integer or None
        Mininum allowed value.
    maxval :  integer or None
        Maximum allowed value.
    allowed_single_chars : str
        String containing allowed valid characters.
    question_mark : bool
        If True, display question mark after prompt.

    Returns
    -------
    result : integer
        Read value.

    """

    return read_value(ftype=int,
                      prompt=prompt,
                      default=default,
                      minval=minval,
                      maxval=maxval,
                      allowed_single_chars=allowed_single_chars,
                      question_mark=question_mark)