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What's wrong with nullable columns in composite primary keys?
...
Primary keys are for uniquely identifying rows. This is done by comparing all parts of a key to the input.
Per definition, NULL cannot be part of a successful comparison. Even a comparison to itself (NULL = NULL) will fail. This means a key containing NULL would not work.
Additonally, NULL is al...
What's the easiest way to escape HTML in Python?
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< to &lt;
> to &gt;
& to &amp;
That is enough for all HTML.
EDIT: If you have non-ascii chars you also want to escape, for inclusion in another encoded document that uses a different encoding, like Craig says, just use:
data.encode('ascii', 'xmlcharrefreplace')
Don't for...
Android: Difference between onInterceptTouchEvent and dispatchTouchEvent?
... are woefully inadequate about explaining this.
dispatchTouchEvent is actually defined on Activity, View and ViewGroup. Think of it as a controller which decides how to route the touch events.
For example, the simplest case is that of View.dispatchTouchEvent which will route the touch event to ei...
How to get a JavaScript object's class?
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ES5 has aditionally Object.getPrototypeOf()
– Christoph
Aug 8 '09 at 18:52
29
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Total memory used by Python process?
...os
import psutil
process = psutil.Process(os.getpid())
print(process.memory_info().rss) # in bytes
On my current Python 2.7 install with psutil 5.6.3, the last line should be
print(process.memory_info()[0])
instead (there was a change in the API).
Note: do pip install psutil if it is not in...
Are nested try/except blocks in python a good programming practice?
...EAFP.
Personally, I prefer to avoid nesting when it's not necessary:
def __getattribute__(self, item):
try:
return object.__getattribute__(item)
except AttributeError:
pass # fallback to dict
try:
return self.dict[item]
except KeyError:
raise Attrib...
UILabel with text of two different colors
...ike this:
NSMutableAttributedString *text =
[[NSMutableAttributedString alloc]
initWithAttributedString: label.attributedText];
[text addAttribute:NSForegroundColorAttributeName
value:[UIColor redColor]
range:NSMakeRange(10, 1)];
[label setAttributedText: text];
...
Encode String to UTF-8
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Technically speaking, byte[] doesn't have any encoding. Byte array PLUS encoding can give you string though.
– Peter Štibraný
Apr 20 '11 at 14:34
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What is the correct way to make a custom .NET Exception serializable?
More specifically, when the exception contains custom objects which may or may not themselves be serializable.
7 Answers
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How to easily resize/optimize an image size with iOS?
...its original size, I'm planning on resizing the image to something a bit smaller to save on space/performance.
18 Answers
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