(i<len(self.students) 我无法理解啊？它不应该是学生的编号吗？求大神解释一下

1. ```class Student:
   def init(self,No,Name,Gender,Age):
   self.No=No
   self.Name=Name
   self.Gender=Gender
   self.Age=Age

   def show(self):
   print("%-16s %-16s %-8s %-4d" %(self.No,self.Name,self.Gender,self.Age))

   class StudentList:
   def init(self):
   self.students = []
   def show(self):
   print("%-16s %-16s %-8s %-4s" % ("No","Name","Gender","Age"))
   for s in self.students:
   s.show()
   def __insert(self,s):
   i = 0
   while (i < len(self.students) and s.No > self.students[i].No):
   i = i + 1
   if (i < len(self.students) and s.No == self.students[i].No):
   print(s.No + " 已经存在")
   return False
   self.students.insert(i,s)
   print("增加成功")
   return True

if (i < len(self.students) and s.No == self.students[i].No):
首先判断i是否超过下标了（这个不涉及编号，判断的是数组长度），然后判断当前这个元素和你要查找的是否相同。