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Python Python Collections (2016, retired 2019) Slices Slice Functions

Posted by Moath Mha
.a{fill-rule:evenodd;}techdegree
Moath Mha
Python Web Development Techdegree Student 1,663 Points

I'm stuck at unit 2 Challenge Task 2 of 4

"Make a new function named first_and_last_4. It'll accept a single iterable but, this time, it'll return the first four and last four items as a single value."

could you please explain what do you mean by "as a single value." ?

slices.py 
def first_4(iterable):
    return iterable[0:4]

def last_4(iterable):
    return iterable[-1:-5:-1]


def first_and_last_4(iterable):
    l1 = first_4(iterable)
    l2 = last_4(iterable)
    return l1 + l2

nums = [1,2,3,4,5,6,7,8,9]

listo = first_and_last_4(nums)
print(listo)

1 Answer

Tyler B
Tyler B
5,787 Points
Tyler B
Tyler B
5,787 Points

As you have last_4 written now your list is returned as [1, 2, 3, 4, 9, 8, 7, 6] changing it to 

def last_4(iterable):
    return iterable[-4:]

everything else in your code looks great and you should get the value as you expect.

Moath Mha
.a{fill-rule:evenodd;}techdegree
Moath Mha
Python Web Development Techdegree Student 1,663 Points

thanks. it worked!