Input with filter by type and characters with Python in a Linux terminal

select_input.py

#!/bin/env python
# -*- coding: utf-8 -*-

# Author.....: Junior Polegato
# Date.......: 13 Jun 2013
# Description: Input with filter by type and characters with
#              Python in a Linux terminal

import sys, tty, termios
import locale

CODING = locale.setlocale(locale.LC_ALL, '').split('.')[-1]

def select_input(prompt, valids, return_type, maximum, auto_exit=True,
                                is_invisible=False, invisible_char='*'):
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    tty.setraw(fd)
    sys.stdout.write(prompt)
    if return_type == bool:
        maximum = 1
        if not valids:
            valids = '01NY'
        else:
            valids = valids.upper()
    if type(valids) == str:
        valids = valids.decode(CODING)
    ret = ''
    while True:
        c = ''
        while True:
            t = sys.stdin.read(1)
            try: # coding test
                c = (c + t).decode(CODING)
            except:
                c += t
                continue
            try: # return type test
                if c == '\r':
                    break
                if return_type == str:
                    c.encode(CODING)
                elif return_type != bool:
                    return_type(c)
                break
            except:
                sys.stdout.write('\x07') # Beep
                c = ''
                continue
        if c == '\r': # Enter
            if ret: break
        elif c == '\x7F' and ret: # Backspace
            sys.stdout.write('\b \b')
            ret = ret[:-1]
        elif len(ret) < maximum and (not valids or
                        return_type == bool and c.upper() in valids or
                        c in valids): # Valid
            if is_invisible:
                sys.stdout.write(invisible_char)
            else:
                sys.stdout.write(c)
            ret += c
            if len(ret) == maximum and auto_exit:
                break
        else: # Invalid
            sys.stdout.write('\x07') # Beep
    sys.stdout.write('\r\n')
    termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
    if return_type == str:
        return ret.encode(CODING)
    elif return_type == bool:
        return bool(valids.index(c.upper()) % 2)
    return return_type(ret)

if __name__ == "__main__":
    idade = select_input('Idade: ', None, int, 2)
    print type(idade), idade

    characters = ("ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                  "abcdefghijklmnopqrstuvwxyz"
                  "ÃÀÁÂÉÊÍÕÓÔÚÜÇÄËÏÖÑÈÌÒÙÎÛÝŸÅÆ"
                  "ãàáâéêíõóôúüçäëïöñèìòùîûýÿåæ ")
    nome = select_input('Nome: ', characters, unicode, 30, False)
    print type(nome), nome

    characters = ("ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                  "abcdefghijklmnopqrstuvwxyz"
                  "ÃÀÁÂÉÊÍÕÓÔÚÜÇÄËÏÖÑÈÌÒÙÎÛÝŸÅÆ"
                  "ãàáâéêíõóôúüçäëïöñèìòùîûýÿåæ ")
    amigo = select_input('Amigo: ', characters, str, 30, False)
    print type(amigo), amigo

    tem_carro = select_input('Tem carro? ', '01NSNY', bool, 1)
    print type(tem_carro), tem_carro

    senha_numerica = select_input('Senha: ', None, int, 6, True, True)
    print type(senha_numerica), "%06i" % senha_numerica