-destfiles = map (lambda f: os.path.join (dest_dir, insert_suffix (os.path.basename (f))), sourcefiles)
+def relative_path (f):
+ if source_dir == '.':
+ return f
+ return f[len (source_dir) + 1:]
+
+destfiles = [os.path.join (dest_dir, insert_suffix (relative_path (f))) for f in sourcefiles]
+
+destdirs = set ([os.path.dirname (dest) for dest in destfiles])
+[os.makedirs (d) for d in destdirs if not os.path.exists (d)]