第 008讲：了不起的分支和循环02

课堂内容

1. 判断各个成绩段的级别

score = int(input ("成绩"))
if 90 <= score <= 100:
print ('A')
elif 80 <score <=90:
print ('B')
elif 70<score <=80:
print ('C')
elif 0<score <=60:
print ('D')

score = int(input ('成绩'))

if 100>= score >= 90:

print ('A')

elif 90> score >= 80:
print ('B')
elif 80> score >= 60:
print ('C')
elif 60> score >= 0:
print ('D')

2. 三元操作符：

x= 4, y=5

if x < y 

 small = x:

else

small = y

small = x if x <y else y (如果想x<y的值是真的，small等于x; 否则small等于y)

3. assert 断言：

if assert后面的条件是假，程序自动崩溃并抛出AssertionError