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How to tell if a tag failed to load
I'm dynamically adding <script> tags to a page's <head> , and I'd like to be able to tell whether the loading failed in some way -- a 404, a script error in the loaded script, whatever.
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Update multiple rows in same query using PostgreSQL
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This is wrong... You will update all rows, even if it is not '123' nor '345'. You should use WHERE column_b IN ('123','456')...
– MatheusOl
Sep 14 '13 at 3:54
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成功熬了四年还没死？一个IT屌丝创业者的深刻反思 - 资讯 - 清泛网 - 专注C...
...升级为Nginx，在Mac上装Ubuntu，Ubuntu里再装个虚拟机去跑Mac OS……
IT青年们也喜欢升级自己的人生，从程序员升级到项目经理，再升级到技术总监或产品总监，再升级到合伙人……
在不断追求升级的过程中，所面临的一个很...
What does `:_*` (colon underscore star) do in Scala?
...tes: MetaData, scope: NamespaceBinding,
child: Node*)
which is called as
new Elem(prefix, label, attributes, scope,
child1, child2, ... childN)
but here there is only a sequence, not child1, child2, etc. so this allows the result sequence to be used as the input to the constru...
Two way/reverse map [duplicate]
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1
>>> del d['foo']
>>> d['bar']
Traceback (most recent call last):
File "<stdin>", line 7, in <module>
KeyError: 'bar'
I'm sure I didn't cover all the cases, but that should get you started.
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Django set default form values
...ch is explained here
You have two options either populate the value when calling form constructor:
form = JournalForm(initial={'tank': 123})
or set the value in the form definition:
tank = forms.IntegerField(widget=forms.HiddenInput(), initial=123)
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@property retain, assign, copy, nonatomic in Objective-C
...gners opted for the safer of the two solutions. In fact nonatomic is generally the better choice as it omits extremely expensive thread locks. The only reason to use atomic is if your property might be set from multiple threads (in which case omitting it can lead to an over-release or a leak).
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How to make a class JSON serializable
...t;>> magic(f)
'{"fname": "/foo/bar"}'
In that case you can merely call json.dumps(f.__dict__).
If you want more customized output then you will have to subclass JSONEncoder and implement your own custom serialization.
For a trivial example, see below.
>>> from json import JSONE...
How do I correctly clone a JavaScript object?
... if you know its name, but I don't know of any way to discover it automatically.
Yet another snag in the quest for an elegant solution is the problem of setting up the prototype inheritance correctly. If your source object's prototype is Object, then simply creating a new general object with {} wil...
Saving a Numpy array as an image
... Remember to scale the values to the right range for PNG, usually 0..255. The value ranges in neural networks are frequently 0..1 or -1..1.
– Tomáš Gavenčiak
Mar 31 '18 at 18:49
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