Simplify run function

bigchaindb/utils.py

@@ -180,8 +180,11 @@ class Lazy:
     def run(self, instance):
         last = instance
 
-        for method, (args, kwargs) in zip(self.stack[::2], self.stack[1::2]):
-            last = getattr(last, method)(*args, **kwargs)
+        for item in self.stack:
+            if isinstance(item, str):
+                last = getattr(last, item)
+            else:
+                last = last(*item[0], **item[1])
 
         self.stack = []
         return last

tests/test_utils.py

@@ -141,7 +141,19 @@ def test_is_genesis_block_returns_true_if_genesis(b):
 
 def test_lazy_execution():
     from bigchaindb.utils import Lazy
+
     l = Lazy()
     l.split(',')[1].split(' ').pop(1).strip()
     result = l.run('Like humans, cats tend to favor one paw over another')
     assert result == 'cats'
+
+    class Cat:
+        def __init__(self, name):
+            self.name = name
+
+    cat = Cat('Shmui')
+
+    l = Lazy()
+    l.name.upper()
+    result = l.run(cat)
+    assert result == 'SHMUI'