equi function in python

equi.py

def equi(l):
    """Finds the equilibirum point in a list `l`.
    
    The equilibrium point is the index within the list where the sum of
    elements to the left is equal to the sum of the elements to the right.
    
    Args:
        l (list): A list of integers.
       
    Returns:
        int or None: The index of the equilibrium point if there is one.
    """
    left, right = 0, sum(l)
    for i, n in l:
        if left == right:
            return i
        left += n
        right -= n