getpass不起作用

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

# login 模塊中登錄時輸入密碼，想用getPass模塊實現密碼的不回顯操作。
#如下：

import getpass
ret = input("welcome to the system:please make a choice-1 or 2")
if ret == '1':
    user = input("請輸入用戶名：")
    pwd = getpass.getpass("請輸入密碼：")

　　

#結果：
#在pycharm中根本不起作用，用官方帶的IDLE顯示如下：
    """
    welcome to the system:please make a choice-1 or 21
    請輸入用戶名：wuwuwu

    Warning (from warnings module):
      File "C:\Program Files\Python36\lib\getpass.py", line 100
        return fallback_getpass(prompt, stream)
    GetPassWarning: Can not control echo on the terminal.
    Warning: Password input may be echoed.
    請輸入密碼：123456
    用戶名不存在
    >>> 
    """

# 命令行界面中測試可行，getpass模塊只能用於命令行界面！
# stack overflow 上 有大神如是說：
"""
Use an actual terminal -- that is, an environment where stdin, 
stdout and stderr are connected to /dev/tty, or another PTY-compliant device.

The IDLE REPL does not meet this requirement.
"""