state retention

progrmoiz · progrmoiz · commit ab9cbc86f324 · 2018-01-18T10:57:12.000+05:00
diff --git a/state_retention.py b/state_retention.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+from __future__ import print_function
+
+
+# nonlocal 3.x
+def tester(start):
+    state = start
+
+    def nested(label):
+        nonlocal state
+        print(label, state)
+        state += 1
+    return nested
+
+
+# nested global 2.x, 3.x
+def tester1(start):
+    global gstate
+    gstate = start
+
+    def nested(label):
+        global gstate
+        print(label, gstate)
+        gstate += 1
+    return nested
+
+
+# with mutables
+def tester2(start):
+    state = [start]
+
+    def nested(label):
+        print(label, state[0])
+        state[0] += 1
+    return nested
+
+
+# function attr
+def tester3(start):
+
+    def nested(label):
+        print(label, nested.state)
+        nested.state += 1
+    nested.state = 0
+    return nested
+
+
+# class
+class tester4(object):
+
+    def __init__(self, start):
+        self.state = start
+
+    def __call__(self, label):
+        print(label, self.state)
+        self.state += 1
+
+
+if __name__ == '__main__':
+    for test in (tester, tester1, tester2, tester3, tester4):
+        f = test(0)
+        f('name: %s, state:' % test.__name__)
+        f('name: %s, state:' % test.__name__)
+        f('name: %s, state:' % test.__name__)
+        f('name: %s, state:' % test.__name__)
+        print()
+    print('done')
