Submitting pickling toolbox

counter.py

@@ -5,35 +5,45 @@
 from pickle import dump, load
 
 def update_counter(file_name, reset=False):
-	""" Updates a counter stored in the file 'file_name'
-
-		A new counter will be created and initialized to 1 if none exists or if
-		the reset flag is True.
-
-		If the counter already exists and reset is False, the counter's value will
-		be incremented.
-
-		file_name: the file that stores the counter to be incremented.  If the file
-				   doesn't exist, a counter is created and initialized to 1.
-		reset: True if the counter in the file should be rest.
-		returns: the new counter value
-
-	>>> update_counter('blah.txt',True)
-	1
-	>>> update_counter('blah.txt')
-	2
-	>>> update_counter('blah2.txt',True)
-	1
-	>>> update_counter('blah.txt')
-	3
-	>>> update_counter('blah2.txt')
-	2
-	"""
-	pass
+    """ Updates a counter stored in the file 'file_name'
+
+        A new counter will be created and initialized to 1 if none exists or if
+        the reset flag is True.
+
+        If the counter already exists and reset is False, the counter's value will
+        be incremented.
+
+        file_name: the file that stores the counter to be incremented.  If the file
+                doesn't exist, a counter is created and initialized to 1.
+        reset: True if the counter in the file should be rest.
+        returns: the new counter value
+
+    >>> update_counter('blah.txt',True)
+    1
+    >>> update_counter('blah.txt')
+    2
+    >>> update_counter('blah2.txt',True)
+    1
+    >>> update_counter('blah.txt')
+    3
+    >>> update_counter('blah2.txt')
+    2
+    """
+    counter = 0
+    if exists(file_name) and not reset:
+        f = open(file_name, 'r+')
+        counter = load(f)
+        f.seek(0,0)
+    else:
+        f = open(file_name, 'w')
+    counter += 1
+    dump(counter, f)
+    return counter
+
 
 if __name__ == '__main__':
 	if len(sys.argv) < 2:
 		import doctest
 		doctest.testmod()
 	else:
-		print "new value is " + str(update_counter(sys.argv[1]))
+		print "new value is " + str(update_counter(sys.argv[1]))