Python - Combinación sin repetir

lista=["a","b","c","d","e"]

for i in lista:

    for j in lista:

        for k in lista:

            print(i,j,k)

#-*- coding: utf -8 -*-

lista=["a","b","c","d","e"]

for i in lista:

    for j in lista:

        for k in lista:

            if i != j and i!=k and j!= k:

                print(i,j,k)