From 15a0887772f9733cc4eaeadcbda1f7223cb32e28 Mon Sep 17 00:00:00 2001
From: Per A Brodtkorb <per.andreas.brodtkorb@gmail.com>
Date: Thu, 8 Sep 2016 13:40:56 +0200
Subject: [PATCH] Replace dict.keys() with list(dict) in order to make it
 python 3 compatible.

---
 wafo/misc.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/wafo/misc.py b/wafo/misc.py
index 3c0f493..0081c92 100644
--- a/wafo/misc.py
+++ b/wafo/misc.py
@@ -2283,8 +2283,8 @@ def stirlerr(n):
 
 
 def _get_max_deadweight(**ship_property):
-    names = ship_property.keys()
-    _assert(len(names) == 1, 'Only one keyword allowed!')
+    names = list(ship_property)
+    _assert(len(ship_property) == 1, 'Only one ship property allowed!')
     name = names[0]
     value = np.array(ship_property[name])
     valid_props = dict(le='length', be='beam', dr='draught',