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What's the difference between identifying and non-identifying relationships?
...t make the foreign key to the parent part of the child's primary key. Formally, the "right" way to do this is to make the foreign key part of the child's primary key. But the logical relationship is that the child cannot exist without the parent.
Example: A Person has one or more phone numbers. ...
Determine the type of an object?
...object, and isinstance() to check an object’s type against something. Usually, you want to use isistance() most of the times since it is very robust and also supports type inheritance.
To get the actual type of an object, you use the built-in type() function. Passing an object as the only param...
What does T&& (double ampersand) mean in C++11?
...e in the draft C++11 standard, but are not true for the final one! Specifically, it says at various points that rvalue references can bind to lvalues, which was once true, but was changed.(e.g. int x; int &&rrx = x; no longer compiles in GCC) – drewbarbs Jul 13 '14 at 16:12
The biggest d...
Enabling auto layout in iOS 6 while remaining backwards compatible with iOS 5
...ve of your .app file. Does having two targets make that process harder at all? Thanks.
– Crystal
May 16 '13 at 2:55
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Getting the last element of a list
...ist[-1] gets the last element, some_list[-2] gets the second to last, etc, all the way down to some_list[-len(some_list)], which gives you the first element.
You can also set list elements in this way. For instance:
>>> some_list = [1, 2, 3]
>>> some_list[-1] = 5 # Set the last e...
.rar, .zip files MIME Type
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actually there's another MIME TYPE for zip, and that's: application/x-zip-compressed
– Kiyarash
Oct 6 '14 at 19:21
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Django - what is the difference between render(), render_to_response() and direct_to_template()?
...and spanking new shortcut for render_to_response in 1.3 that will automatically use RequestContext that I will most definitely be using from now on.
2020 EDIT: It should be noted that render_to_response() was removed in Django 3.0
https://docs.djangoproject.com/en/1.8/topics/http/shortcuts/#rend...
Using IPython notebooks under version control
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Here is my solution with git. It allows you to just add and commit (and diff) as usual: those operations will not alter your working tree, and at the same time (re)running a notebook will not alter your git history.
Although this can probably be adapted to ...
How to find out the number of CPUs using python
...sing Python. The result should be user/real as output by time(1) when called with an optimally scaling userspace-only program.
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How can javascript upload a blob?
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To do basically $('input[type=file]').value=blob
– William Entriken
Aug 9 '13 at 21:36
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