在sys.stdin.readline的地方有效，在仅input（）的地方有效

Question

我在同一代码中使用了sys.stdin.readline（）和input（）。两次都工作。以下是代码：

import sys
print('how much was your meal')
price = int(input())
print('how much would you like to tip in percentage')
tip = int(input())
tipamount = price * (tip/100)
print('your tip amount is %s' %tipamount + 'dollars')

第二个代码：

#import sys
#price = int(sys.stdin.readline())
#print('how much would you like to tip in percentage')
#tip = int(sys.stdin.readline())
#tipamount = price * (tip/100)
#print('your tip amount is %s' %tipamount + 'dollars') 

但是当我在下面的代码中使用sys.stdin.readline时，它不起作用。相反，input（）起作用了。有人可以解释一下sys.stdin.readline为什么在第一个代码中起作用而在这个代码中不起作用吗？

import sys
print('are you looking to study digital media in australia?')
answer = str(sys.stdin.read())
if answer == 'yes':
print('Deakin University has one of the best Digital Science Program!')