example code for serializing chapter

examples/serialize.py

@@ -0,0 +1,50 @@
+import pickle
+import json
+import time
+
+def custom_encoder(python_object):
+    if isinstance(python_object, time.struct_time):
+        return {'__class__': 'time.asctime',
+                '__value__': time.asctime(python_object)}
+    if isinstance(python_object, bytes):
+        return {'__class__': 'bytes',
+                '__value__': list(python_object)}
+    raise TypeError(repr(python_object) + ' is not JSON serializable')
+
+def custom_decoder(json_object):
+    if '__class__' in json_object:
+        if json_object['__class__'] == 'time.asctime':
+            return time.strptime(json_object['__value__'])
+        if json_object['__class__'] == 'bytes':
+            return bytes(json_object['__value__'])
+    return json_object
+
+if __name__ == '__main__':
+    entry = {}
+    entry['title'] = 'Dive into history, 2009 edition'
+    entry['article_link'] = 'http://diveintomark.org/archives/2009/03/27/dive-into-history-2009-edition'
+    entry['comments_link'] = None
+    entry['internal_id'] = b'\xde\xd5\xb4\xf8'
+    entry['tags'] = ('diveintopython', 'docbook', 'html')
+    entry['published'] = True
+    entry['published_date'] = time.strptime('Fri Mar 27 22:20:42 2009')
+    
+    with open('entry.pickle', 'wb') as f:
+        pickle.dump(entry, f)
+
+    with open('entry.pickle', 'rb') as f:
+        entry2 = pickle.load(f)
+
+    print(entry == entry2)
+    print(type(entry['tags']))
+    print(type(entry2['tags']))
+
+    with open('entry.json', 'w', encoding = 'utf-8') as f:
+        json.dump(entry, f, default = custom_encoder)
+
+    with open('entry.json', 'r', encoding = 'utf-8') as f:
+        entry2 = json.load(f, object_hook = custom_decoder)
+
+    print(entry == entry2)
+    print(type(entry['tags']))
+    print(type(entry2['tags']))