有if elif条件问题python2.7

Question

当我运行以下条件时，条件课程级别 6 超过 260 分，数学为 0，我没有得到“不幸的是，您不符合升入第三级的要求，至少 260 分并通过数学”是必要的。” 信息。

但是，当在条件课程级别 5 下运行时，我确实得到了超过 260 分和 0 分的数学信息？

if course == 5:
    print"Your total CAO points are " ,total

elif course == 6:
        print"Your total CAO points are " , total*1.25
        total= total*1.25

if total >=260: 
    if math>=25:
        print "You are eligible to progress to third level"

elif total >=260:
     math=0
        print "Unfortunately you do not meet the requirements to progress to third level, At least 260 points and a pass in Mathematics are required."

elif total <=260:
    math=0
    print "Unfortunately you do not meet the requirements to progress to third level, At least 260 points and a pass in Mathematics are required."

Answer 1

一旦 if-elif-else 套件中的一个测试通过，其他任何测试都不会被检查。 在您的代码中，您的elif的条件与您的if相同。 这意味着永远无法访问elif下的代码。

if total >= 260: 
    if math >= 25: # failing this if-statement does not negate the "if total >= 260"
        print "You are eligible to progress to third level"

elif total >= 260:  # will never be reached because it's identical to prior if-statement
    math=0
    print "Unfortunately you do not meet the requirements to progress to third level, At least 260 points and a pass in Mathematics are required."

elif total <= 260: # is 260 in our out? if 260 is a pass change from <= to <
    math=0
    print "Unfortunately you do not meet the requirements to progress to third level, At least 260 points and a pass in Mathematics are required."

有一种更好的方法来编写您的条件。 您的错误消息包含单词and ：

至少需要 260 分和数学及格。

所以在你的条件下使用and来简化你的逻辑：

if total >= 260 and math >= 25:     # must meet both conditions
    print "You are eligible to progress to third level"
else:
    math = 0
    print "Unfortunately you do not meet the requirements to progress to third level. "\
        "At least 260 points and a pass in Mathematics are required."