为什么我的函数不打印 try-except-else 结果？

心中带点小风骚 2年前 python 321

原文标题 ：Why is my function not printing the try-except-else result?

我有一个家庭作业问题：

“编写一个程序，要求用户输入最小和最大年龄。然后调用函数 BMI_calculator() 来计算和打印给定年龄范围的平均 BMI。你的脚本应该包含一个 try-except-else 机制，它将(1) 如果您输入的年龄小于或大于患者列表中的年龄，则打印单独的错误消息，并且 (2) 提示用户重新输入数据，直到给出适当的年龄范围”

我的代码有什么问题？我无法检索有关年龄范围 BMI 的数据。

CSV 文件：我在函数中使用的 CSV 文件

def BMI_calculator(min_age, max_age):

file_obj = open(r"C:\Users\ahana\OneDrive\Desktop\intro toprogramming\assignment_8\patient_data.csv")

data = file_obj.read()

file_obj.close()

#data processing
lines = data.split("\n")
del lines [-1]

#18 lines
line1 = lines[1].split(",")
line2 = lines[2].split(",")
line3 = lines[3].split(",")
line4 = lines[4].split(",")
line5 = lines[5].split(",")
line6 = lines[6].split(",")
line7 = lines[7].split(",")
line8 = lines[8].split(",")
line9 = lines[9].split(",")
line10 = lines[10].split(",")
line11 = lines[11].split(",")
line12 = lines[12].split(",")
line13 = lines[13].split(",")
line14 = lines[14].split(",")
line15 = lines[15].split(",")
line16 = lines[16].split(",")
line17 = lines[17].split(",")
line18 = lines[18].split(",")

processed = [line1, line2, line3, line4, line5, line6, line7, line8, line9, line10, line11, line12, line13, line14, line15, line16, line17, line18]

#obtain height and weight columns
age = []
for line in processed:
    age.append(line[2])

height = []
for line in processed:
    height.append(line[3])

weight = []
for line in processed:
    weight.append(line[4])

min_value = min(age)

max_value = max(age)

target_weight = []
target_height = []

for line in processed:
    if int(line[2]) >= min_age and int(line[2]) <= max_age:
        target_weight.append(line[4])
        target_height.append(line[3])
try:
    bmi = ((target_weight/len(target_weight)) / (target_height / len(target_height))**2 )*703

except:
    if int(min_age) < int(min_value):
        print("Minimum age value too small. Try Again.")
    elif int(max_age) > int(max_value):
        print("Maximum age value too large. Try Again.")
        
else:
    print(f"The average BMI for the given age range {max_age} to {min_age} is {bmi}.")

原文链接：https://stackoverflow.com//questions/71962533/why-is-my-function-not-printing-the-try-except-else-result

我来回复

dbakr 评论

听起来你的老师希望你创建自定义错误类来抛出，试试这个：

class ValueTooHighError(Error):
    pass
class ValueTooLowError(Error):
    pass


file_obj = open(r"C:\Users\ahana\OneDrive\Desktop\intro toprogramming\assignment_8\patient_data.csv")

data = file_obj.read()

file_obj.close()
#----left out some code for conciseness----#
min_value = min(age)
max_value = max(age)

target_weight = []
target_height = []

for line in processed:
    try:
        if int(line[2]) >= min_age and int(line[2]) <= max_age:
            target_weight.append(line[4])
            target_height.append(line[3])
        else:
            if(int(line[2])<min_age):
                raise ValueTooLowError
            else:
                raise ValueTooHighError
    except:
        ValueTooLowError:
            print("Minimum age value too small. Try Again.")
        ValueTooHighError:
            print("Maximum age value too large. Try Again.")

bmi = ((sum(target_weight)/len(target_weight)) / (sum(target_height) / len(target_height))**2 )*703
print(f"The average BMI for the given age range {max_age} to {min_age} is {bmi}.")

2年前 0条评论

Stanley 评论
这里发生了很多事情，首先我将使用 try-except 块解决您的实际问题。我相信您希望except代码在年龄值超出范围时运行，但您需要实际生成异常以使try语句捕获：
```
def calcBMI(minimum, maximum, val):
  if val<minimum or val>maximum:
    raise ValueError
  # do stuff

try:
  bmi = calcBMI(min_age, max_age, value)
except ValueError:
  print("Error")
else:
  print(bmi)
```
还有很多不好的形式，你正在使用 18 条几乎相同的独立行来做一些只需要一条的事情！填写processedlist的那18行可以写成：
```
processed = [line.split(",") for line in lines]
```
另一件事是您运行相同的 for 循环 3 次来填充年龄、身高和体重列表。你可以这样做：
```
for line in processed:
  age.append(line[2])
  height.append(line[3])
  weight.append(line[4])
```
2年前 0条评论

为什么我的函数不打印 try-except-else 结果？

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