Tape equilibrium

    #!/usr/bin/python3.5
class tape:
    def __init__(self,Sum,p):
        self.sum_a=Sum
        self.p=p
    def SUM(self):
        Min=Sum
        for i in range(p):
            sum_left=sum(a[:i])
            sum_right=Sum-sum_left
            if (abs(sum_right-sum_left)<Min):
                Min=abs(sum_right-sum_left)
        return Min

            

def unlimited():
    a=[]
    Sum=0
    while True:
        i=input("a:")
        if i =='q'or i=='':
            return (a,Sum )
        
        else:
            j=int(i)
            a.append(j)
            Sum=Sum+j
            
a,Sum=unlimited()
print("sum_a: ",Sum)
p=int(input("p : "))
t=tape(Sum,p)
MIN=t.SUM()
print("MIN : ",MIN)

Hi,
getting input from user is not expected.
you should consider a pointer to array and pass this array with its length to the function.