>>> lst = [1, 2, 3, 4]
>>> 
>>> sum(i * i for i in lst)
30
>>>

  
>>> lst1 = [1, 2, 3, 4]
>>> lst2 = [5, 6, 7, 8]
>>> 
>>> sum(i * j for i, j in zip(lst1, lst2))
70
>>>

  
>>> def dot(a, b):
...     return sum(i * j for i, j in zip(a, b))
... 
>>> a = [1, 2, 3, 4]
>>> b = [5, 6, 7, 8]
>>> 
>>> dot(a, a)
30
>>> dot(a, b)
70
>>>