我正在尝试在下图中的等级类别之间进行映射.然后我希望能够调用一个函数,将等级转换为等效格式的相同等级.例如：
def convert(num,letter,gpa):
"""Converts a grade into an equivalent grade. The desired output will be
specified by -1 and the grade format not to be involved in the conversion
will be specified by None. When converting to GPA,the minimum of the gpa
range will be returned."""
>>> convert(83,None,-1)
>>> 'A-'
>>>convert(-1,'B+',None)
>>>77
解决方法
我可能会做这样的事情,它避免了条件分支,并且很清楚你在转换时想要做什么.
class GradeRange:
def __init__(self,pct,ltr,gpa):
self.pct = pct
self.ltr = ltr
self.gpa = gpa
class GradeTable:
def __init__(self):
self.ranges = [
GradeRange(range(0,50),'F',0.0),GradeRange(range(50,53),'D-',0.7),GradeRange(range(53,57),'D',1.0),GradeRange(range(57,60),'D+',1.3),GradeRange(range(60,63),'C-',1.7),GradeRange(range(63,67),'C',2.0),GradeRange(range(67,70),'C+',2.3),GradeRange(range(70,73),'B-',2.7),GradeRange(range(73,77),'B',3.0),GradeRange(range(77,80),3.3),GradeRange(range(80,85),'A-',3.7),GradeRange(range(85,90),'A',4.0),GradeRange(range(90,101),'A+',]
def convert_pct(self,pct):
for r in self.ranges:
if pct in r.pct:
return r.ltr,r.gpa
def convert_ltr(self,ltr):
for r in self.ranges:
if r.ltr == ltr:
return r.pct[0],r.gpa
def convert_gpa(self,gpa):
for r in self.ranges:
if r.gpa == gpa:
return r.pct[0],r.ltr