feat(example): modules

Author: ashegde

codes/session_4/message.py

@@ -0,0 +1,9 @@
+# message.py is a module (imported inside module.py)
+# so execute python3 module.py
+# Start typing below commands and see the output
+
+def hello(name):
+  print('Hello ' + name)
+
+def welcome(name):
+  print('Welcome ' + name)

codes/session_4/module.py

@@ -0,0 +1,19 @@
+# Open terminal > 
+#   python3 module.py
+#   python3 module.py <String>
+# Start typing below commands and see the output
+
+# Import module
+from message import hello, welcome
+# from message import *
+# import message # then use as message.hello
+
+print(hello('Ashwin'))
+print(welcome('Ashwin'))
+
+if __name__ == '__main__':
+  import sys
+  if len(sys.argv) > 1:
+    hello(sys.argv[1])
+  else:
+    hello('Unknown')