Merge pull request #346 from tv3141/variable_swapping_exercise_using_…

…list

Use list instead of tuple in variable swapping exercise

_episodes/03-lists.md

@@ -468,7 +468,7 @@ Omitting ending index: ["sep", "oct", "nov", "dec"]
 > Compare it to:
 >
 > ~~~
-> left, right = right, left
+> left, right = [right, left]
 > ~~~
 > {: .python}
 >
@@ -488,7 +488,7 @@ Omitting ending index: ["sep", "oct", "nov", "dec"]
 > > ~~~
 > > {: .output}
 > >
-> >In the first case we used a temporary variable `temp` to keep the value of `left` before we overwrite it with the value of `right`. In the second case, we pack `right` and `left` into a tuple and then unpack it again into `left` and `right`.
+> >In the first case we used a temporary variable `temp` to keep the value of `left` before we overwrite it with the value of `right`. In the second case, `right` and `left` are packed into a list and then unpacked into `left` and `right`.
 > {: .solution}
 {: .challenge}