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

how to use slice to get first four and last four values in a list ?

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.

slices.py
def first_4(list):
  return(list[0:4], list(0:-4])

list (0,-4) returns values from index -1 to fourth last item. this is what I wrote - def first_and_last_4(list): return(list[0:4],[-4::1])

for some reason, I get an error.

1 Answer

Steven Parker
Steven Parker
231,007 Points

You're getting close there, but there's a few issues:

  • the name of the new function is "first_and_last_4"
  • the function from task 1 ("first_4") should still be as it was when it passed task 1
  • you'll want to combine the two slices together but not make a tuple of them
  • the second slice starts with a parenthesis instead an open brace
  • check the arguments on the second slice — "last 4" should probably start somewhere other than 0
Steven Parker
Steven Parker
231,007 Points

That's better, but you left off the parameter name on that 2nd slice. Also, you probably don't want the "last 4" slice to end at index 1.

And you're still making a tuple (,) instead of combining the slices +