Bend over backward to avoid ResourceWarnings.

src/ZODB/tests/blob_transaction.txt

@@ -27,7 +27,8 @@ Aborting a blob add leaves the blob unchanged:
 
     >>> blob1._p_oid
     >>> blob1._p_jar
-    >>> with blob1.open() as fp: fp.read()
+    >>> with blob1.open() as fp:
+    ...     fp.read()
     'this is blob 1'
 
 It doesn't clear the file because there is no previously committed version: 
@@ -51,7 +52,8 @@ state:
 
     >>> with blob1.open('w') as file:
     ...     _ = file.write(b'this is new blob 1')
-    >>> with blob1.open() as fp: fp.read()
+    >>> with blob1.open() as fp:
+    ...     fp.read()
     'this is new blob 1'
     >>> fname = blob1._p_blob_uncommitted
     >>> os.path.exists(fname)
@@ -62,7 +64,8 @@ state:
     False
     >>> blob1._p_blob_uncommitted
 
-    >>> with blob1.open() as fp: fp.read()
+    >>> with blob1.open() as fp:
+    ...     fp.read()
     'this is blob 1'
 
 Opening a blob gives us a filehandle.  Getting data out of the
@@ -103,12 +106,12 @@ when we start)::
 
     >>> bool(blob1a._p_changed)
     False
-    >>> with blob1a.open('r') as fp: fp.read()
+    >>> with blob1a.open('r') as fp:
+    ...     fp.read()
     'this is blob 1'
-    >>> blob1afh3 = blob1a.open('a')
-    >>> bool(blob1a._p_changed)
-    True
-    >>> _ = blob1afh3.write(b'woot!')
+    >>> with blob1a.open('a') as blob1afh3:
+    ...     assert(bool(blob1a._p_changed))
+    ...     _ = blob1afh3.write(b'woot!')
     >>> blob1afh3.close()
 
 We can open more than one blob object during the course of a single
@@ -124,11 +127,14 @@ Since we committed the current transaction above, the aggregate
 changes we've made to blob, blob1a (these refer to the same object) and
 blob2 (a different object) should be evident::
 
-    >>> with blob1.open('r') as fp: fp.read()
+    >>> with blob1.open('r') as fp:
+    ...     fp.read()
     'this is blob 1woot!'
-    >>> with blob1a.open('r') as fp: fp.read()
+    >>> with blob1a.open('r') as fp:
+    ...     fp.read()
     'this is blob 1woot!'
-    >>> with blob2.open('r') as fp: fp.read()
+    >>> with blob2.open('r') as fp:
+    ...     fp.read()
     'this is blob 3'
 
 We shouldn't be able to persist a blob filehandle at commit time
@@ -136,8 +142,9 @@ We shouldn't be able to persist a blob filehandle at commit time
 pickled appears to be particulary unhelpful for casual users at the
 moment)::
 
-    >>> root1['wontwork'] = blob1.open('r')
-    >>> transaction.commit()
+    >>> with blob1.open('r') as f:
+    ...     root1['wontwork'] = f
+    ...     transaction.commit()
     Traceback (most recent call last):
     ...
     TypeError: ...
@@ -160,7 +167,8 @@ connections should result in a write conflict error::
     >>> with blob1c4.open('a') as blob1c4fh1:
     ...     _ = blob1c4fh1.write(b'this is from connection 4')
     >>> tm1.commit()
-    >>> with root3['blob1'].open('r') as fp: fp.read()
+    >>> with root3['blob1'].open('r') as fp:
+    ...     fp.read()
     'this is blob 1woot!this is from connection 3'
     >>> tm2.commit()
     Traceback (most recent call last):
@@ -170,10 +178,12 @@ connections should result in a write conflict error::
 After the conflict, the winning transaction's result is visible on both
 connections::
 
-    >>> with root3['blob1'].open('r') as fp: fp.read()
+    >>> with root3['blob1'].open('r') as fp:
+    ...     fp.read()
     'this is blob 1woot!this is from connection 3'
     >>> tm2.abort()
-    >>> with root4['blob1'].open('r') as fp: fp.read()
+    >>> with root4['blob1'].open('r') as fp:
+    ...     fp.read()
     'this is blob 1woot!this is from connection 3'
 
 You can't commit a transaction while blob files are open:
@@ -205,21 +215,22 @@ We do support optimistic savepoints:
     >>> connection5 = database.open()
     >>> root5 = connection5.root()
     >>> blob = ZODB.blob.Blob()
-    >>> blob_fh = blob.open("w")
-    >>> _ = blob_fh.write(b"I'm a happy blob.")
-    >>> blob_fh.close()
+    >>> with blob.open("w") as blob_fh:
+    ...     _ = blob_fh.write(b"I'm a happy blob.")
     >>> root5['blob'] = blob
     >>> transaction.commit()
-    >>> with root5['blob'].open("r") as fp: fp.read()
+    >>> with root5['blob'].open("r") as fp:
+    ...     fp.read()
     "I'm a happy blob."
-    >>> blob_fh = root5['blob'].open("a")
-    >>> _ = blob_fh.write(b" And I'm singing.")
-    >>> blob_fh.close()
-    >>> with root5['blob'].open("r") as fp: fp.read()
+    >>> with root5['blob'].open("a") as blob_fh:
+    ...     _ = blob_fh.write(b" And I'm singing.")
+    >>> with root5['blob'].open("r") as fp:
+    ...     fp.read()
     "I'm a happy blob. And I'm singing."
     >>> savepoint = transaction.savepoint(optimistic=True)
 
-    >>> with root5['blob'].open("r") as fp: fp.read()
+    >>> with root5['blob'].open("r") as fp:
+    ...     fp.read()
     "I'm a happy blob. And I'm singing."
 
 Savepoints store the blobs in temporary directories in the temporary
@@ -241,7 +252,8 @@ We support non-optimistic savepoints too:
 
     >>> with root5['blob'].open("a") as file:
     ...     _ = file.write(b" And I'm dancing.")
-    >>> with root5['blob'].open("r") as fp: fp.read()
+    >>> with root5['blob'].open("r") as fp:
+    ...     fp.read()
     "I'm a happy blob. And I'm singing. And I'm dancing."
     >>> savepoint = transaction.savepoint()
 
@@ -255,7 +267,8 @@ Again, the savepoint creates a new savepoints directory:
     ...     _ = file.write(b" And the weather is beautiful.")
     >>> savepoint.rollback()
 
-    >>> with root5['blob'].open("r") as fp: fp.read()
+    >>> with root5['blob'].open("r") as fp:
+    ...     fp.read()
     "I'm a happy blob. And I'm singing. And I'm dancing."
     >>> transaction.abort()
 
@@ -275,12 +288,12 @@ file that can be opened.
     >>> connection6 = database.open()
     >>> root6 = connection6.root()
     >>> blob = ZODB.blob.Blob()
-    >>> blob_fh = blob.open("w")
-    >>> _ = blob_fh.write(b"I'm a happy blob.")
-    >>> blob_fh.close()
+    >>> with blob.open("w") as blob_fh:
+    ...     _ = blob_fh.write(b"I'm a happy blob.")
     >>> root6['blob'] = blob
     >>> transaction.commit()
-    >>> with open(blob.committed()) as fp: fp.read()
+    >>> with open(blob.committed()) as fp:
+    ...     fp.read()
     "I'm a happy blob."
 
 We can also read committed data by calling open with a 'c' flag:
@@ -344,7 +357,8 @@ uncommitted changes:
     BlobError: Uncommitted changes
 
     >>> transaction.commit()
-    >>> with open(blob.committed()) as fp: fp.read()
+    >>> with open(blob.committed()) as fp:
+    ...     fp.read()
     "I'm a happy blob."
 
 You can't open a committed blob file for writing:
@@ -397,7 +411,8 @@ And we shouldn't be able to read the data that we saved:
 
 Of course the old data should be unaffected:
 
-    >>> with open(blob_storage.loadBlob(blob._p_oid, oldserial)) as fp: fp.read()
+    >>> with open(blob_storage.loadBlob(blob._p_oid, oldserial)) as fp:
+    ...     fp.read()
     "I'm a happy blob."
 
 Similarly, the new object wasn't added to the storage: