Ux design addons

Try to make exercises a bit easier by explaining more. Also a bit of reworking of the order in which texts appear in the is_atlantic function example.

lectures/user-experience/static/safe_copy.py

-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import shutil
@@ -13,11 +13,11 @@ def parse_args():
     return args
 
 
-def main():
-    args = parse_args()
+def copy_file(args):
     if not os.access(args.outfIle, os.F_OK):
         shutil.copyfile(args.sOurce, args.outfIle)
 
 
 if __name__ == "__main__":
-    main()
+    args = parse_args()
+    copy_file(args)