CSc 120: List to String (Version 2)
Expected Behavior
Write a function concat_elements(slist, startpos, stoppos), where
slist is a list of strings and startpos and stoppos are
integers, that concatenates the elements of slist starting at
position startpos and ending at position stoppos (inclusive)
and returns the resulting string.
Your code should behave reasonably for all values of startpos and
stoppos: if startpos is negative, concatenation should start with
the first element of slist; if stoppos ≥ len(slist),
concatenation should stop at the last element of slist. If
startpos > stoppos it should return the empty string.
See the examples below.
Programming Requirements
Solve this problem without explicitly iterating over the
list. One way to do this involves a combination of slicing and join().
Examples
-
concat_elements(['aa','bb','cc','dd'], 1, 3)
return value: 'bbccdd'
-
concat_elements(['aa','bb','cc','dd'], -1, 1)
return value: 'aabb'
-
concat_elements(['aa','bb','cc','dd'], -9, 9)
return value: 'aabbccdd'
-
concat_elements(['aa','bb','cc','dd'], 3, 3)
return value: 'dd'
-
concat_elements(['aa','bb','cc','dd'], 3, 1)
return value: ''