s13

class DoesNotExist(Exception):
    pass
class MultipleObjectsReturned(Exception):
    pass
class InvalidField(Exception):
    pass

class Student:

    def __init__(self,name, age, score):
        self.name = name
        self.student_id = None
        self.age = age
        self.score = score
    
    def __repr__(self):
        return "Student(student_id={0}, name={1}, age={2}, score={3})".format(self.student_id,self.name,self.age,self.score)
    
    
    def delete(self):
        sql_query='delete from student where student_id={}'.format(self.student_id)
        write_data(sql_query)
    
    
    def save(self):
        if self.student_id is None:
            query="insert into student(name,age,score) values ('{}',{},{})".format(self.name,self.age,self.score)
            write_data(query)
            q1='select student_id from student where name="{}" and age={} and score={}'.format(self.name,self.age,self.score)
            a=read_data(q1)   
            self.student_id=a[0][0]
        else:
            sql_query="update student set student_id={},name='{}',age={},score={} where student_id={}".format(self.student_id,self.name,self.age,self.score,self.b)
            write_data(sql_query) 
            
    @classmethod
    def get(cls,**kid):
        for x,y in kid.items():
            cls.a=x
            cls.b=y
            if str(x) not in ('name','age','score','student_id'):
                raise InvalidField 
        query="select * from student where {} = '{}'".format(cls.a,cls.b)
        obj=read_data(query)
        if len(obj)>1:
            raise MultipleObjectsReturned
        elif len(obj)==0:
            raise DoesNotExist
        elif len(obj)==1:
            c=Student(obj[0][1],obj[0][2],obj[0][3])
            c.student_id=obj[0][0]
            return c
     
    @classmethod
    def filter(cls,**kid):
        cls.li=[]
        cls.operator={'lt':'<','lte':'<=','gt':'>','gte':'>=','neq':'!=','in':'in','contain':''}
        
        
        if(len(kid))>=1:
            l=[]
            for x,y in kid.items():
                    cls.a=x
                    cls.b=y
                    
                    field=cls.a
                    field=field.split('__')
                    if field[0] not in ('name','age','score','student_id'):
                            raise InvalidField 
            
                    if(len(field))==1:
                        query=" {}='{}'".format(cls.a,cls.b)
                    elif field[1]=='contains':
                        query=" {} like '%{}%'".format(field[0],cls.b)
                    elif field[1]=='in':
                        query=" {} {} {}".format(field[0],cls.operator[field[1]],tuple(cls.b))
                    else:    
                        query="{} {} '{}'".format(field[0],cls.operator[field[1]],cls.b)
                
                    l.append(query)
                    
            x = " and ".join(tuple(l))       
            query= "select * from student where "+x
            
            
        #print(query)            
        obj=read_data(query)
        for i in range(len(obj)):
            c=Student(obj[i][1],obj[i][2],obj[i][3])
            c.student_id=obj[i][0]
            cls.li.append(c)
        return cls.li    
                
        
    
        
def write_data(sql_query):
	import sqlite3
	connection = sqlite3.connect("selected_students.sqlite3")
	crsr = connection.cursor() 
	crsr.execute("PRAGMA foreign_keys=on;") 
	crsr.execute(sql_query) 
	connection.commit() 
	connection.close()

def read_data(sql_query):
	import sqlite3
	connection = sqlite3.connect("selected_students.sqlite3")
	crsr = connection.cursor() 
	crsr.execute(sql_query) 
	ans= crsr.fetchall()  
	connection.close() 
	return ans

#selected_students = Student.filter(age__lte=30)
#print(selected_students)

#selected_students = Student.filter(age__contains="Maude Vanhorne")
#print(selected_students)
#selected_students = Student.filter(age=15,name="Jesse Couch")
#print(selected_students)
#selected_students = Student.filter(age__in = [25, 34], score__lt=50)