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Are foreign keys really necessary in a database design?
... ON DELETE CASCADE. This means that if you have one table containing users and another containing orders or something, then deleting a user could automatically delete all orders that point to that user.
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Python: Bind an Unbound Method?
...descriptors, so you can bind them by calling their __get__ method:
bound_handler = handler.__get__(self, MyWidget)
Here's R. Hettinger's excellent guide to descriptors.
As a self-contained example pulled from Keith's comment:
def bind(instance, func, as_name=None):
"""
Bind the functi...
#define macro for debug printing in C?
...on:
#ifdef DEBUG
#define DEBUG_TEST 1
#else
#define DEBUG_TEST 0
#endif
And then use DEBUG_TEST where I used DEBUG.
If you insist on a string literal for the format string (probably a good idea anyway), you can also introduce things like __FILE__, __LINE__ and __func__ into the output, which can...
How do I increase the cell width of the Jupyter/ipython notebook in my browser?
...th of the ipython notebook in my browser. I have a high-resolution screen, and I would like to expand the cell width/size to make use of this extra space.
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deleting rows in numpy array
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The simplest way to delete rows and columns from arrays is the numpy.delete method.
Suppose I have the following array x:
x = array([[1,2,3],
[4,5,6],
[7,8,9]])
To delete the first row, do this:
x = numpy.delete(x, (0), axis=0)
To del...
Catch browser's “zoom” event in JavaScript
...the user changes the zoom in a page?
I simply want to catch a "zoom" event and respond to it (similar to window.onresize event).
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How to make links in a TextView clickable?
...attributes on my TextView to match what was in the demo.
<TextView
android:id="@+id/text2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/txtCredits"/>
That solved it. Pretty difficult to uncover and fix.
Important: Don't forg...
Why should I not wrap every block in “try”-“catch”?
...
A method should only catch an exception when it can handle it in some sensible way.
Otherwise, pass it on up, in the hope that a method higher up the call stack can make sense of it.
As others have noted, it is good practice to have an unhandled exception handler (with loggin...
How do I remove a project configuration in Visual Studio 2008?
...t to remove.
In the dialog that pops up, mark each unwanted configuration and select "Remove".
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?? Coalesce for empty string?
Something I find myself doing more and more is checking a string for empty (as in "" or null) and a conditional operator.
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