diff --git a/README.md b/README.md
index 7bc2d32..02bed9f 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@ Lei Mao
 
 Protocol Buffer, also known as Protobuf, is Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data. Protocol Buffers Version 3 (Proto3) was released in 2016. However, the official [tutorials](https://developers.google.com/protocol-buffers/docs/cpptutorial) on the Google protobuf website are still for Proto2. The official [samples](https://github.com/protocolbuffers/protobuf/tree/master/examples) are using Proto3 and CMake, however, its CMake is not standard and many of its macros were not documented on the official CMake website.
 
-In this repository, I re-implemented Google's official Protobuf C++ and Python example using Proto3 and CMake with the best practice. I also put code comments as many as possible to make sure the code is human readable and easy to understand. 
+In this repository, I re-implemented Google's official Protobuf C++ and Python example using Proto3 and CMake with the best practice. I also put code comments as many as possible to make sure the code is human readable and easy to understand.
 
 ## Dependencies
 
@@ -60,7 +60,7 @@ All the executable files would be generated in `build/bin` directory.
 
 ### Run Examples
 
-The C++ and Python serialization and deserialization can be used interchangeably (C++ serialization + C++ deserialization, C++ serialization + Python deserialization, Python serialization + Python deserialization, Python serialization + C++ deserialization), as the data formats are all generated from the same `proto` file and they are all the same. 
+The C++ and Python serialization and deserialization can be used interchangeably (C++ serialization + C++ deserialization, C++ serialization + Python deserialization, Python serialization + Python deserialization, Python serialization + C++ deserialization), as the data formats are all generated from the same `proto` file and they are all the same.
 
 #### Add People Using C++
 
@@ -69,27 +69,27 @@ $ ./build/bin/add_people build/data.pb # Add people to data
 build/data.pb: File not found.  Creating a new file.
 Add person to address book? yes | no
 yes
-Enter person ID number: 
+Enter person ID number:
 12345
-Enter name: 
+Enter name:
 Lei Mao
-Enter email address (blank for none): 
+Enter email address (blank for none):
 dukeleimao@gmail.com
-Enter a phone number (or leave blank to finish): 
+Enter a phone number (or leave blank to finish):
 +1123456789
-Is this a mobile, home, or work phone? mobile | home | work 
+Is this a mobile, home, or work phone? mobile | home | work
 home
-Enter a phone number (or leave blank to finish): 
+Enter a phone number (or leave blank to finish):
 
 Add person to address book? yes | no
 yes
-Enter person ID number: 
+Enter person ID number:
 54321
-Enter name: 
+Enter name:
 Andrew Ng
-Enter email address (blank for none): 
+Enter email address (blank for none):
 andrew.ng@stanford.edu
-Enter a phone number (or leave blank to finish): 
+Enter a phone number (or leave blank to finish):
 
 Add person to address book? yes | no
 no
@@ -98,7 +98,7 @@ no
 #### List People Using C++
 
 ```bash
-$ python examples-python/add_people.py build/data.pb # Read data
+$ ./build/bin/list_people build/data.pb # Read data
 Person ID: 12345
   Name: Lei Mao
   E-mail address: dukeleimao@gmail.com
@@ -113,7 +113,7 @@ Person ID: 54321
 #### Add People Using Python
 
 ```bash
-$ python examples-python/list_people.py build/data.pb 
+$ python examples-python/add_people.py build/data.pb
 build/data.pb: File not found.  Creating a new file.
 Add person to address book? yes | no
 yes
@@ -122,13 +122,13 @@ Enter name: Lei Mao
 Enter email address (blank for none): dukeleimao@gmail.com
 Enter a phone number (or leave blank to finish): +1123456789
 Is this a mobile, home, or work phone? home
-Enter a phone number (or leave blank to finish): 
+Enter a phone number (or leave blank to finish):
 Add person to address book? yes | no
 yes
 Enter person ID number: 54321
 Enter name: Andrew Ng
 Enter email address (blank for none): andrew.ng@stanford.edu
-Enter a phone number (or leave blank to finish): 
+Enter a phone number (or leave blank to finish):
 Add person to address book? yes | no
 no
 ```
@@ -136,7 +136,7 @@ no
 #### List People Using Python
 
 ```bash
-$ python examples-python/list_people.py build/data.pb 
+$ python examples-python/list_people.py build/data.pb
 Person ID: 12345
   Name: Lei Mao
   E-mail address: dukeleimao@gmail.com
diff --git a/examples-python/add_people.py b/examples-python/add_people.py
index 3af8852..cfbba23 100644
--- a/examples-python/add_people.py
+++ b/examples-python/add_people.py
@@ -2,6 +2,8 @@
 import sys
 sys.path.append("build/protos")
 import addressbook_pb2
+from time import time
+from addressbook_pb2 import google_dot_protobuf_dot_timestamp__pb2 as timestamp
 
 try:
   raw_input          # Python 2
@@ -36,6 +38,8 @@ def PromptForAddress(person):
     else:
       print("Unknown phone type; leaving as default value.")
 
+    person.last_updated.CopyFrom(timestamp.Timestamp(seconds=int(time())))
+
 
 # Main procedure:  Reads the entire address book from a file,
 #   adds one person based on user input, then writes it back out to the same
diff --git a/examples-python/list_people.py b/examples-python/list_people.py
index 4700e50..ea23677 100644
--- a/examples-python/list_people.py
+++ b/examples-python/list_people.py
@@ -3,7 +3,7 @@
 import sys
 sys.path.append("build/protos")
 import addressbook_pb2
-
+from datetime import datetime
 
 # Iterates though all people in the AddressBook and prints info about them.
 def ListPeople(address_book):
@@ -22,6 +22,9 @@ def ListPeople(address_book):
         print("  Work phone #:", end=" ")
       print(phone_number.number)
 
+    last_update = person.last_updated
+    if last_update.seconds != 0:
+      print("  Updated", datetime.fromtimestamp(last_update.seconds))
 
 # Main procedure:  Reads the entire address book from a file and prints all
 #   the information inside.