Use with open() to ensure the file gets close()d

cclauss · web-flow · commit 05ca48e02ef6 · 2017-09-19T21:08:59.000+08:00
`process_data()`is an undefined name in this context
diff --git a/cookbook/c04/p16_iterate_while.py b/cookbook/c04/p16_iterate_while.py
@@ -22,11 +22,10 @@ def reader2(s, size):
 
 def iterate_while():
     CHUNKSIZE = 8192
-    f = open('/etc/passwd')
-    for chunk in iter(lambda: f.read(10), ''):
-        n = sys.stdout.write(chunk)
+    with open('/etc/passwd') as f:
+        for chunk in iter(lambda: f.read(10), ''):
+            n = sys.stdout.write(chunk)
 
 
 if __name__ == '__main__':
     iterate_while()
-
