diff --git a/interactive_brokers.py b/interactive_brokers.py
index 10971f9..c8d1166 100644
--- a/interactive_brokers.py
+++ b/interactive_brokers.py
@@ -71,54 +71,54 @@ def isFileForBroker(cls, filename):
 
     @classmethod
     def parseFileToTxnList(cls, filename, tax_year):
-        f = open(filename)
-        # First 2 lines are headers.
-        f.readline()
-        f.readline()
-        txns = csv.reader(f, delimiter=',', quotechar='"')
+        with open(filename) as f:
+            # First 2 lines are headers.
+            f.readline()
+            f.readline()
+            txns = csv.reader(f, delimiter=',', quotechar='"')
 
-        txn_list = []
-        part = None
-        box = None
-        entry_code = None
+            txn_list = []
+            part = None
+            box = None
+            entry_code = None
 
-        for row in txns:
-            if row[0] == 'Part' and len(row) == 3:
-                box = None
-                if row[1] == 'I':
-                    part = 1
-                elif row[1] == 'II':
-                    part = 2
-                else:
-                    utils.Warning('unknown part line: "%s"\n' % row)
-            elif row[0] == 'Box' and len(row) == 3:
-                if row[1] == 'A' or row[1] == 'B' or row[1] == 'C':
-                    box = row[1]
-                    entry_code = cls.DetermineEntryCode(part, box)
-                else:
-                    utils.Warning('unknown box line: "%s"\n' % row)
-            elif row[0] == 'Data' and len(row) == 9:
-                if not entry_code:
-                    utils.Warning(
-                        'ignoring data: "%s" as the code is not defined\n')
-                    continue
-                txn = utils.Transaction()
-                txn.desc = row[1]
-                txn.buyDateStr = row[3]
-                txn.sellDateStr = row[4]
-                year = cls.TryParseYear(txn.sellDateStr)
-                txn.saleProceeds = cls.ParseDollarValue(row[5])
-                txn.costBasis = cls.ParseDollarValue(row[6])
-                if row[7]:
-                    txn.adjustment = cls.ParseDollarValue(row[7])
-                txn.entryCode = entry_code
-                if tax_year and year and year != tax_year:
-                    utils.Warning('ignoring txn: "%s" as the sale is not from %d\n' %
-                                  (txn.desc, tax_year))
-                else:
-                    txn_list.append(txn)
-                txn = None
-            elif (row[0] != 'Header' and row[0] != 'Footer') or len(row) != 9:
-                utils.Warning('unknown line: "%s"\n' % row)
+            for row in txns:
+                if row[0] == 'Part' and len(row) == 3:
+                    box = None
+                    if row[1] == 'I':
+                        part = 1
+                    elif row[1] == 'II':
+                        part = 2
+                    else:
+                        utils.Warning('unknown part line: "%s"\n' % row)
+                elif row[0] == 'Box' and len(row) == 3:
+                    if row[1] == 'A' or row[1] == 'B' or row[1] == 'C':
+                        box = row[1]
+                        entry_code = cls.DetermineEntryCode(part, box)
+                    else:
+                        utils.Warning('unknown box line: "%s"\n' % row)
+                elif row[0] == 'Data' and len(row) == 9:
+                    if not entry_code:
+                        utils.Warning(
+                            'ignoring data: "%s" as the code is not defined\n')
+                        continue
+                    txn = utils.Transaction()
+                    txn.desc = row[1]
+                    txn.buyDateStr = row[3]
+                    txn.sellDateStr = row[4]
+                    year = cls.TryParseYear(txn.sellDateStr)
+                    txn.saleProceeds = cls.ParseDollarValue(row[5])
+                    txn.costBasis = cls.ParseDollarValue(row[6])
+                    if row[7]:
+                        txn.adjustment = cls.ParseDollarValue(row[7])
+                    txn.entryCode = entry_code
+                    if tax_year and year and year != tax_year:
+                        utils.Warning('ignoring txn: "%s" as the sale is not from %d\n' %
+                                      (txn.desc, tax_year))
+                    else:
+                        txn_list.append(txn)
+                    txn = None
+                elif (row[0] != 'Header' and row[0] != 'Footer') or len(row) != 9:
+                    utils.Warning('unknown line: "%s"\n' % row)
 
-        return txn_list
+            return txn_list