如果您将字符串放入 score 的参数中，为什么我除了捕捉之外没有尝试？

Question

#Write a program to prompt for a score between 0.0 and 1.0.
#If the score is out of range print an error.
#If the score is between 0.0 and 1.0, print a grade using the following table:
#Score Grade >=0.9 A >=0.8 B >=0.7 C >=0.6 D <0.6 F

def computegrade(score):
    try:
        score1 = float(score)
        if score1 <= 1.0 and score1 >= 0.9:        
            grade = "A"
        elif score1 < 0.9 and score1 >= 0.8:
            grade = "B"
        elif score1 < 0.8 and score1 >= 0.7:
            grade = "C"
        elif score1 < 0.7 and score1 >= 0.6:
            grade = "D"
        elif score1 < 0.6 and score1 > 0:
            grade = "F"
        else:
            grade = "ERROR: You did not enter a number or you entered a number out of the range of 0.0 and 1.0!"
        print(grade) 
    except:
        print("ERROR: You did not enter a number or you entered a number out of the range of 0.0 and 1.0!")

无论我输入 0.0 和 1.0 范围之外的整数还是输入该范围内的整数，一切似乎都按预期工作。我创建了一个尝试，除非用户输入一个字符串作为分数。但它似乎没有抓住它，我不知道为什么。

Answer 1

我试过了，效果很好。确保输入是一个不能转换为浮点数的字符串，你应该没问题。

def computegrade(score):
    try:
        score1 = float(score)
        if score1 <= 1.0 and score1 >= 0.9:
            grade = "A"
        elif score1 < 0.9 and score1 >= 0.8:
            grade = "B"
        elif score1 < 0.8 and score1 >= 0.7:
            grade = "C"
        elif score1 < 0.7 and score1 >= 0.6:
            grade = "D"
        elif score1 < 0.6 and score1 > 0:
            grade = "F"
        else:
            grade = "ERROR: You did not enter a number or you entered a     number out of the range of 0.0 and 1.0!"
        print(grade)
    except:
        print("ERROR: You did not enter a number or you entered a number out of the range of 0.0 and 1.0!")
computegrade("fire")

输出：

ERROR: You did not enter a number or you entered a number out of the range of 0.0 and 1.0!