From a9ccdb19ce5c57730294e45017ad1c4e4ead1105 Mon Sep 17 00:00:00 2001
From: Jim Rybarski <jim@rybarski.com>
Date: Fri, 9 Oct 2015 22:18:12 -0500
Subject: [PATCH] resolves #96: added context manager

---
 README.md              | 8 ++++++++
 nd2reader/interface.py | 9 ++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 83cbd6b..65afe92 100644
--- a/README.md
+++ b/README.md
@@ -52,6 +52,14 @@ You can also get some metadata about the nd2 programatically:
 30528
 ```
 
+`Nd2` is also a context manager, if you care about that sort of thing:
+
+```
+>>> import nd2reader
+>>> with nd2reader.Nd2("/path/to/my_images.nd2") as nd2:
+...     for image in nd2:
+...         do_something(image)
+
 ### Images
 
 `Image` objects are just Numpy arrays with some extra metadata bolted on:
diff --git a/nd2reader/interface.py b/nd2reader/interface.py
index 54d8607..9f3403b 100644
--- a/nd2reader/interface.py
+++ b/nd2reader/interface.py
@@ -12,12 +12,19 @@ class Nd2(object):
 
     """
     def __init__(self, filename):
+        self._filename = filename
         self._fh = open(filename, "rb")
         major_version, minor_version = get_version(self._fh)
         parser = get_parser(self._fh, major_version, minor_version)
         self._driver = parser.driver
         self._metadata = parser.metadata
-        self._filename = filename
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if self._fh is not None:
+            self._fh.close()
         
     def __repr__(self):
         return "\n".join(["<ND2 %s>" % self._filename,