lista = ['a', 'b', 'c']
item = 'a'
outro_item = 'b'
# aqui estou tentando fazer lista[0,1]=lista[1,0] com indexof diretamente:
lista[lista.index(item)],lista[lista.index(outro_item)]= lista[lista.index(outro_item)],lista[lista.index(item)]
# não trocou!
print(lista[0]) # a
print(lista[1]) # b
print(lista[2]) # c
bGlzdGEgPSBbJ2EnLCAnYicsICdjJ10gIAoKaXRlbSA9ICdhJyAgCm91dHJvX2l0ZW0gPSAnYicgCgojIGFxdWkgZXN0b3UgdGVudGFuZG8gZmF6ZXIgbGlzdGFbMCwxXT1saXN0YVsxLDBdIGNvbSBpbmRleG9mIGRpcmV0YW1lbnRlOgpsaXN0YVtsaXN0YS5pbmRleChpdGVtKV0sbGlzdGFbbGlzdGEuaW5kZXgob3V0cm9faXRlbSldPSBsaXN0YVtsaXN0YS5pbmRleChvdXRyb19pdGVtKV0sbGlzdGFbbGlzdGEuaW5kZXgoaXRlbSldCgojIG7Do28gdHJvY291IQpwcmludChsaXN0YVswXSkgIyBhCnByaW50KGxpc3RhWzFdKSAjIGIgCnByaW50KGxpc3RhWzJdKSAjIGM=