I need to do some special operation for the last element in a list. Is there any better way than this?
array = [1,2,3,4,5] for i, val in enumerate(array): if (i+1) == len(array): // Process for the last element else: // Process for the other element
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Answer
for item in list[:-1]: print "Not last: ", item print "Last: ", list[-1]
If you don’t want to make a copy of list, you can make a simple generator:
# itr is short for "iterable" and can be any sequence, iterator, or generator def notlast(itr): itr = iter(itr) # ensure we have an iterator prev = itr.next() for item in itr: yield prev prev = item # lst is short for "list" and does not shadow the built-in list() # 'L' is also commonly used for a random list name lst = range(4) for x in notlast(lst): print "Not last: ", x print "Last: ", lst[-1]
Another definition for notlast:
import itertools notlast = lambda lst:itertools.islice(lst, 0, len(lst)-1)