From b92ba0af3e853ccc0c47eaafe72abdd46837f827 Mon Sep 17 00:00:00 2001
From: lumbric <lumbric@gmail.com>
Date: Thu, 11 Feb 2021 21:04:36 +0100
Subject: [PATCH] Close files after opening them

Using open() as context manager is the preferred way to close files to
guarantee exception safety. This commit solves an occasional
ResourceWarning, when CylP is used in unit tests run by pytest. There
are more direct calls of open() without context manager in setup.py.
---
 cylp/__init__.py | 3 ++-
 cylp/py/QP/QP.py | 7 +++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/cylp/__init__.py b/cylp/__init__.py
index 19f5ffe7..2c7c299f 100644
--- a/cylp/__init__.py
+++ b/cylp/__init__.py
@@ -1,4 +1,5 @@
 import os
 from os.path import realpath, join
 currentDir = os.path.dirname(realpath(__file__))
-__version__ = open(join(currentDir, 'VERSION')).read().strip()
+with open(join(currentDir, 'VERSION')) as f:
+    __version__ = f.read().strip()
diff --git a/cylp/py/QP/QP.py b/cylp/py/QP/QP.py
index 4fbbf534..50f05245 100644
--- a/cylp/py/QP/QP.py
+++ b/cylp/py/QP/QP.py
@@ -1259,15 +1259,14 @@ def Wolfe(self, method='w'):
         qobj = 0.5 * x.T * G * x + np.dot(c, x) - self.objectiveOffset
 
         print(s.iteration)
-        f = open('qpout', 'a')
-        st = '%s %s %s %s %s %s %s\n' % (self.filename.ljust(30), method.ljust(2),
+        with open('qpout', 'a') as f:
+            st = '%s %s %s %s %s %s %s\n' % (self.filename.ljust(30), method.ljust(2),
                 str(round(s.objectiveValue, 5)).ljust(8),
                 str(round(qobj, 5)).ljust(8),
                 str(timeToMake),
                 str(timeToSolve),
                 str(timeToMake + timeToSolve))
-        f.write(st)
-        f.close()
+            f.write(st)
 
 #        print(checkComp(s.primalVariableSolution['k1'],
 #                        s.primalVariableSolution['zk1']))