大约有 17,000 项符合查询结果（耗时：0.0307秒） [XML]
django : using select_related and get_object_or_404 together
Is there any way of using get_object_or_404 and select_related together or any other way to achieve the result of using these two together(except from putting it in try/except)??
...
How to fix: “UnicodeDecodeError: 'ascii' codec can't decode byte”
... declared in your code using the u prefix to strings. E.g.
>>> my_u = u'my ünicôdé strįng'
>>> type(my_u)
<type 'unicode'>
Unicode strings may also come from file, databases and network modules. When this happens, you don't need to worry about the encoding.
Gotchas
C...
Query for documents where array size is greater than 1
...r: [{name: {$exists: false}}, {name: {$size: 0}}, {name: {$size: 1}}]})
{ "_id" : ObjectId("511907e3fb13145a3d2e225b"), "name" : [ "George", "Raymond" ] }
{ "_id" : ObjectId("511907e3fb13145a3d2e225c"), "name" : [ "George", "Raymond", "Richard" ] }
{ "_id" : ObjectId("511907e3fb13145a3d2e225d"), "na...
Local variables in nested functions
...s to the function, with the code using an index to reference each cell. pet_function thus has one free variable (cage) which is then referenced via a closure cell, index 0. The closure itself points to the local variable cage in the get_petters function.
When you actually call the function, that cl...
When should Flask.g be used?
...st without change to code.
The application context is popped after teardown_request is called. (Armin's presentation explains this is because things like creating DB connections are tasks which setup the environment for the request, and should not be handled inside before_request and after_request)
...
How does free know how much to free?
...
FYI, for example BSD has malloc_size() to reliably access the block size from an malloc()ed pointer. But there's no reliable, portable way.
– laalto
Oct 5 '09 at 7:53
...
Cross-browser testing: All major browsers on ONE machine
...Safari on a single Windows machine.
Download: http://sandboxie.com/index.php?DownloadSandboxie
Patch: The extended version is required to enable multiple sandboxes at a time. Pay them or visit YouTube.
Running multiple IE/Safari versions simultaneously requires the extended version. If you don't m...
Update multiple rows in same query using PostgreSQL
... one column, it's much more generalizable:
update test as t set
column_a = c.column_a
from (values
('123', 1),
('345', 2)
) as c(column_b, column_a)
where c.column_b = t.column_b;
You can add as many columns as you like:
update test as t set
column_a = c.column_a,
column_c...
Concatenating two one-dimensional NumPy arrays
...There are several possibilities for concatenating 1D arrays, e.g.,
numpy.r_[a, a],
numpy.stack([a, a]).reshape(-1),
numpy.hstack([a, a]),
numpy.concatenate([a, a])
All those options are equally fast for large arrays; for small ones, concatenate has a slight edge:
The plot was created with perf...
How do I find out which keystore was used to sign an app?
...
First, unzip the APK and extract the file /META-INF/ANDROID_.RSA (this file may also be CERT.RSA, but there should only be one .RSA file).
Then issue this command:
keytool -printcert -file ANDROID_.RSA
You will get certificate fingerprints like this:
MD5: B3:4F:BE:07:AA:7...