对于这项任务，我们应该在Python中创建一个课程，我们在这里放3分，并且必须找到学生的平均成绩和成绩。它有效，但我有一个错误。当我输入一个整数（例如73）三次时，它将显示字母等级。但是当我输入一个带小数的数字（例如83.7）三次时它没有显示字母等级，这就是我们需要的那种数字。当我输入带小数的数字时，有没有办法让它显示成绩？为什么它只适用于整个数字？
class grades:
def __init__(self,name,test1,test2,test3,avg):
self.name = name
self.test1 = test1
self.test2 = test2
self.test3 = test3
self.avg = avg
def getName(self):
return self.name
def getTest1(self):
return self.test1
def getTest2(self):
return self.test2
def getTest3(self):
return self.test3
def getAvg(self):
return self.avg
#main:
name = input("Enter the students name: ")
test1 = float(input("Enter the first score: "))
test2 = float(input("Enter the second score: "))
test3 = float(input("Enter the third score: "))
avg = float(test1 + test2 + test3) /3.0
grades1 = grades(name,test1,test2,test3,avg)
grades1.name
grades1.test1
grades1.test2
grades1.test3
grades1.avg
print("The student's name is:" ,grades1.name)
print(grades1.name +"'s test scores are:")
print("---------------------------:")
print("TEST1: \t\t\t",grades1.test1)
print("TEST2: \t\t\t",grades1.test2)
print("TEST3: \t\t\t",grades1.test3)
print(grades1.name +"'s average is: \t",grades1.avg)
##if avg <= 100.0 and avg >= 90.0:
## print(name +"'s grade is: \t A")
##elif avg <= 89.0 and avg >= 80.0:
## print(name +"'s grade is: \t B")
##elif avg <= 79.0 and avg >= 70.0:
## print(name +"'s grade is: \t C")
##elif avg <= 69.0 and avg >= 60.0:
## print(name +"'s grade is: \t D")
##elif avg <= 59.0 and avg >= 0.0:
## print(name +"'s grade is: \t E")
if avg >= 90.0 and avg <= 100.0:
print(name +"'s grade is: \t A")
elif avg >= 80.0 and avg <= 89.0:
print(name +"'s grade is: \t B")
elif avg >= 70.0 and avg <= 79.0:
print(name +"'s grade is: \t C")
elif avg >= 60.0 and avg <= 69.0:
print(name +"'s grade is: \t D")
elif avg >= 0.0 and avg <= 59.0:
print(name +"'s grade is: \t E")
我之前评论一年级部分的原因是因为我尝试了两种方法而没有运气。
这是我尝试的但是没有运气小数
Enter the students name: k
Enter the first score: 89.9
Enter the second score: 89.9
Enter the third score: 89.9
The student's name is: k
k's test scores are:
---------------------------:
TEST1: 89.9
TEST2: 89.9
TEST3: 89.9
k's average is: 89.90000000000002
答案 0 :(得分：3)
问题出在您的if中。当平均值介于89和90，79和80之间时，您就没有任何理由。此外，您不需要在第一个之外的任何and，因为之前的每个检查都将确认and再次检查的内容。您可以将大部分if缩短为单一条件。
if avg > 100 or avg < 0:
#check for out of range grades first
print('Grade out of range')
elif avg >= 90.0:
print(name +"'s grade is: \t A")
# if the elif is reached, we already know that the grade is below 90, because
# it would have been handled by the previous if, if it were >=90
elif avg >= 80.0:
print(name +"'s grade is: \t B")
elif avg >= 70.0: # other wise the previous check will have caught it
print(name +"'s grade is: \t C")
elif avg >= 60.0:
print(name +"'s grade is: \t D")
elif avg >= 0.0:
print(name +"'s grade is: \t E") # should this be 'F' instead of 'E'?
只是因为我是一个好人;）
class Grades:
def __init__(self, name, *tests):
self.name = name
self.tests = list(tests)
@property
def avg(self):
return sum(self.tests)/len(self.tests)
@property
def letter_avg(self):
avg = self.avg
if avg > 100 or avg < 0:
raise ValueError('Grade out of range')
elif avg >= 90.0:
return 'A'
elif avg >= 80.0:
return 'B'
elif avg >= 70.0:
return 'B'
elif avg >= 60.0:
return 'D'
elif avg >= 0.0:
return 'F'
def __iter__(self):
return iter(self.tests)
def __getattr__(self, attr):
"""Allows access such as 'grades.test1' """
if attr.startswith('test'):
try:
num = int(attr[4:])-1
return self.tests[num]
except (ValueError, IndexError):
raise AttributeError('Invalid test number')
else:
raise AttributeError(
'Grades object has no attribute {0}'.format(attr))
def main():
name = input("Enter the students name: ")
test1 = float(input("Enter the first score: "))
test2 = float(input("Enter the second score: "))
test3 = float(input("Enter the third score: "))
grades1 = Grades(name, test1, test2, test3)
print("The student's name is:" , grades1.name)
print(grades1.name +"'s test scores are:")
print("---------------------------:")
for index, test in enumerate(grades1):
print('TEST{0}: \t\t\t{1}'.format(index, test))
print("{0}'s average is {1}".format(grades1.name, grades1.avg))
print("{0}'s average is \t {1}".format(grades1.name, grades1.letter_avg))
if __name__ == '__main__':
main()
答案 1 :(得分：1)
您的if-elif语句未涵盖所有可能的值。例如，如果平均值为89.5，则没有一个块会捕获它。解决此问题的最简单方法是从<=语句中删除if-elif子句，因为它们是不必要的。
if avg >= 90.0:
print(name +"'s grade is: \t A")
elif avg >= 80.0:
print(name +"'s grade is: \t B")
elif avg >= 70.0:
print(name +"'s grade is: \t C")
elif avg >= 60.0:
print(name +"'s grade is: \t D")
else:
print(name +"'s grade is: \t E")
答案 2 :(得分：0)
您遗漏了一些边界情况，例如89.9，79.7，这些平均值不会在您的计划中打印任何等级。
你需要这样的东西：
if avg >= 90.0 and avg <= 100.0:
print(name +"'s grade is: \t A")
elif avg >= 80.0 and avg < 90.0: #should be <90 not 89.0
print(name +"'s grade is: \t B")
elif avg >= 70.0 and avg < 80.0: #should be <80 not 79.0
print(name +"'s grade is: \t C")
elif avg >= 60.0 and avg < 70.0: #should be <70 not 69.0
print(name +"'s grade is: \t D")
elif avg >= 0.0 and avg < 60.0: #should be <60 not 59.0
print(name +"'s grade is: \t E")
<强>演示：
The student's name is: dfgd
dfgd's test scores are:
---------------------------:
TEST1: 89.9
TEST2: 89.9
TEST3: 89.9
dfgd's average is: 89.90000000000002
dfgd's grade is: B
<强>更新
这里的清洁解决方案将是bisect模块：
import bisect
lis = [0,60,70,80,90,100]
grades = list('EDCBA')
ind = bisect.bisect_right(lis,avg) -1
print(name +"'s grade is: \t {}".format(grades[ind]))