why calls python both functions? : I have some problems to understand what happens here...

This is my source:

    class Calc():

	def __init__(self,Ideal,Limit,Value,Debug=None):

		self.Ideal = Ideal
		self.Limit = Limit
		self.Value = Value
		self.Debug = Debug
		self.Grade = self.GetGrade()
		self.LenGrade = self.GetLenGrade()

	def GetGrade(self):
		if self.Debug:
			print('calling GetGrade')
		return Grade

	def GetLenGrade(self):
		if self.Debug:
			print('calling GetLenGrade')
		return Grade

When calling it with

    GradeMinLen += Calc(TargetLen, LimitMinLen, Length ,Debug=1).LenGrade

I get always the output

calling GetGrade

calling GetLenGrade

Why is python calling GetGrade?