1 files changed, 3 insertions, 1 deletions
diff --git a/draw.py b/draw.py
index 70efda7..30a2ffd 100755
--- a/draw.py
+++ b/draw.py
@@ -17,7 +17,7 @@ def roundrobin(*iterables):
             nexts = cycle(islice(nexts, pending))
 
 def draw(filename, nevents):
-    f = h5py.File(filename)
+    f = h5py.File(filename, 'r')
 
     fig = plt.figure()
     for i, dataset in enumerate((f[name] for name in f)):
@@ -37,6 +37,8 @@ def draw(filename, nevents):
         plt.ylabel('Voltage (V)')
         plt.title(dataset.name)
 
+    f.close()
+
     return fig
 
 if __name__ == '__main__':