New Exceptions & Factorial files, and revised bst

exception-handling.py

@@ -0,0 +1,31 @@
+filename = 'exception_data.txt'
+# Outer try block catches file name or file doesn't exist errors.
+try:
+	with open(filename) as fin:
+		for line in fin:
+			# print(line)
+			items = line.split(',')
+			total = 0
+			
+			# Inner try bock catches integer conversion errors.
+			try:
+				for item in items:
+					num = int(item)
+					total += num
+				print('Total = ' + str(total))
+			except:
+				print('Error converting to integer. ', items)
+except:
+	print('Error opening file. ' + filename)
+	
+finally:
+	print('This is our optional finally block. Code here will execute no matter what.')
+	
+	
+# Second example: name Error type in except block; call function from try block.
+def this_fails():
+	x = 1/0
+try:
+	this_fails()
+except ZeroDivisionError as err:
+	print('Handling run-time error:', err)