Quick sort a list of integers in place
Swapping

def swap(l, i, j):
    temp = l[i]
    l[i] = l[j]
    l[j] = temp


Just do:

l[i], l[j] = l[j], l[i] # (a)


You could abstract this into a swap function like you have done, but I probably wouldn't in this case. Matter of taste. Nevertheless, if you do swap the body definition should consist of (a).

Unnecessary variables.

pivot_ind = left
return pivot_ind


Just return left. Write a comment explaining what left is if you need to.