Turning in my Pickle Toolbox

blah.txt

@@ -0,0 +1,2 @@
+I3
+.

blah2.txt

@@ -0,0 +1,2 @@
+I2
+.

counter.py

@@ -1,7 +1,10 @@
 """ A program that stores and updates a counter using a Python pickle file"""
 
-from os.path import exists
+from os.path import exists 
+#Return True if path refers to an existing path. 
+#Returns False for broken symbolic links. 
 import sys
+import pickle
 from pickle import dump, load
 
 def update_counter(file_name, reset=False):
@@ -29,11 +32,39 @@ def update_counter(file_name, reset=False):
 	>>> update_counter('blah2.txt')
 	2
 	"""
-	pass
 
+	counter = 0 
+
+	# If file dne or reset = True we will create counter starting at 1 
+	if exists(file_name) == False or reset == True: 
+		f  = open(file_name,'w') # f is now a file object ready to be written
+		counter = 1 # set counter ready to write to file 
+		pickle.dump(counter,f)
+		return counter
+		f.close()
+
+	# If file exist and reset = False we will add one to counter
+	elif exists(file_name) and reset == False: 
+		f = open(file_name,'r+') # f is now a file object ready to be read and then written 
+		counter = pickle.load(f) # load f as file already exists
+		f.seek(0,0) # moves pointer to start of file to write over previous content
+		counter += 1 # adds 1 to pre-existing counter
+		pickle.dump(counter,f) # update counter in f 
+		return counter 
+		f.close() 
+
 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])) # catches name variable 
+
+
+	# I had a hard time with this, my main difficulty was in sorting out the order of operations to call 
+	# 1) open/create file
+	# 2) if file contains content: load content with pickle
+	# 3) dump new content into file
+	# 4) return content & close file 
+
+

dogs

@@ -0,0 +1,2 @@
+I1
+.

pigs

@@ -0,0 +1,2 @@
+I1
+.