def firstElement (lst):
"""
Retorna el primer elemento de la lista, sin eliminarlo.
"""
if (lst['type']=='ARRAY_LIST'):
return alt.firstElement (lst)
else:
return slt.firstElement (lst)
def test_addFirst(lst, books):
assert slt.isEmpty(lst) == True
assert slt.size(lst) == 0
slt.addFirst(lst, books[1])
assert slt.size(lst) == 1
slt.addFirst(lst, books[2])
assert slt.size(lst) == 2
book = slt.firstElement(lst)
assert book == books[2]
def test_addFirst(lst, books):
assert lts.isEmpty(lst) == True
assert lts.size(lst) == 0
lts.addFirst(lst, books[1])
assert lts.size(lst) == 1
lts.addFirst(lst, books[2])
assert lts.size(lst) == 2
book = lts.firstElement(lst)
assert book == books[2]
def test_addLast(lst, peliculas):
assert slt.isEmpty(lst) == True
assert slt.size(lst) == 0
slt.addLast(lst, peliculas[1])
assert slt.size(lst) == 1
slt.addLast(lst, peliculas[2])
assert slt.size(lst) == 2
pelicula = slt.firstElement(lst)
assert pelicula == peliculas[1]
pelicula = slt.lastElement(lst)
assert pelicula == peliculas[2]
def firstElement(lst):
"""
Retorna el primer elemento de la lista, sin eliminarlo.
Args:
lst
Lista a evaluar
Return::int
El primer elemento dentro de la lista
"""
if (lst['type'] == 'ARRAY_LIST'):
return alt.firstElement(lst)
else:
return slt.firstElement(lst)
def firstElement(lst):
""" Retorna el primer elemento de una lista no vacía. No se elimina el elemento.
Args:
lst: La lista a examinar
Raises:
Exception
"""
try:
if (lst['type'] == 'ARRAY_LIST'):
return alt.firstElement(lst)
else:
return slt.firstElement(lst)
except Exception as exp:
error.reraise(exp, 'List->firstElement: ')
