#! /usr/local/bin/python
# -*- coding: utf-8 -*-




def a2bits(chars):
    """
    Convert a string to its bits representation as a string of 0's and 1's.
    
    >>> a2bits("Hello World!")
    '010010000110010101101100011011000110111100100000010101110110111101110010011011000110010000100001'
    """
    return bin(reduce(lambda x, y : (x<<8)+y, (ord(c) for c in chars), 1))[3:]

def a2bits_list(chars):
    """
    Convert a string to its bits representation as a list of 0's and 1's.
    
    >>>  a2bits_list("Hello Word!")
    ['01001000',
    '01100101',
    '01101100',
    '01101100',
    '01101111',
    '00100000',
    '01010111',
    '01101111',
    '01110010',
    '01101100',
    '01100100',
    '00100001']
    >>> "".join(a2bits_list("Hello World!"))
    '010010000110010101101100011011000110111100100000010101110110111101110010011011000110010000100001'
    """
    return [bin(ord(x))[2:].rjust(8,"0") for x in chars]

def bs(s):
    """
    Convert an int to its bits representation as a string of 0's and 1's.
    """
    return str(s) if s<=1 else bs(s>>1) + str(s&1)