organization in the src structure, modification of README

src/builtin_structures/dicts/setdeault_example.py

@@ -0,0 +1,38 @@
+#!/usr/bin/python3
+# mari von steinkirch @2013
+# steinkirch at gmail
+
+
+def usual_dict(dict_data):
+    newdata = {}
+    for k, v in dict_data:
+        if k in newdata:
+            newdata[k].append(v)
+        else:
+            newdata[k] = [v]
+    return newdata
+
+
+def setdefault_dict(dict_data):
+    newdata = {}
+    for k, v in dict_data:
+        newdata.setdefault(k, []).append(v)
+    return newdata
+
+
+def test_setdef(module_name='this module'):
+    dict_data = (('key1', 'value1'),
+               ('key1', 'value2'),
+               ('key2', 'value3'),
+               ('key2', 'value4'),
+               ('key2', 'value5'),)
+    print(usual_dict(dict_data))
+    print(setdefault_dict(dict_data))
+        
+    s = 'Tests in {name} have {con}!'
+    print(s.format(name=module_name, con='passed'))
+
+
+if __name__ == '__main__':
+    test_setdef()
+