Add a duration class to easily measure the time taken for an operatio…

…n. (#33)

duration.py

@@ -0,0 +1,41 @@
+import datetime
+import time
+
+
+class Duration:
+    """A class to measure duration of an action.
+    Example usage of the class is
+        with Duration('Test Operation') as measure:
+            print('Performing Test operation')
+            ... Do the necessary operations
+            time.sleep(2)
+
+    When the with block ends, it will print out the duration
+    of the operation in the following format
+        Performing Test operation
+        Duration(dd:hh:ss:ms) of Test Operation 0:00:02.000826
+    """
+
+    def __init__(self, operation_name: str = 'undefined'):
+        self.start: datetime.datetime = None
+        self.end: datetime.datetime = None
+        self.operation_name = operation_name
+
+    def __enter__(self):
+        """Records the start time of an operation
+        """
+        self.start = datetime.datetime.now()
+
+    def __exit__(self, exception_type, exception_value, traceback):
+        """Records the end time of an operation
+        Prints the duration between start and end of an operation
+        """
+        self.end = datetime.datetime.now()
+        print(f'Duration(dd:hh:ss:ms) of {self.operation_name} {self.end - self.start}')
+
+
+if __name__ == "__main__":
+    print('Start executing main...')
+    with Duration('Test Operation') as measure:
+        time.sleep(2)
+    print('Done executing main...')