实现程序：
data = int(raw_input("Please input a number between 0 and 128: "))
if 0< data <128:
ch = chr(data)
print ch
else:
print "Error,please input a number between 0 and 128."
运行结果：
www-hhl@wwwhhl-TM4750:~/python/wl_ex1$ python ascii-output.py
Please input a number between 0 and 128: 98
b
www-hhl@wwwhhl-TM4750:~/python/wl_ex1$ python ascii-output.py
Please input a number between 0 and 128: 345
Error,please input a number between 0 and 128.
作者备注：写的还不够完善，用户输入的如果不是0-128之间的数字，应该直接再出现输入页面，这个我还不知道怎么实现，如果你知道，欢迎留言交流。我微信号：hhlwill
