Coletando chars sob demanda em Python

chars.py

class _Getch:
    """Gets a single character from standard input.  Does not echo to the
screen."""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            self.impl = _GetchUnix()

    def __call__(self): return self.impl()


class _GetchUnix:
    def __init__(self):
        import tty, sys

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch


class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()


getch = _Getch()


if __name__ == '__main__':

    print 'Hello, sir! Try type something ;) - Write ";" ends our conversation. ;)'

    may_i_continue = True
    string_query = ''

    while may_i_continue:
        char_data = getch()
        string_query += char_data

        print "String So far: %s" % string_query

        may_i_continue = False if char_data == ';' else True