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MongoDB Many-to-Many Association
... user document:
{name:"Joe"
,roles:["Admin","User","Engineer"]
}
To get all the Engineers, use:
db.things.find( { roles : "Engineer" } );
If you want to maintain the roles in separate documents then you can include the document's _id in the roles array instead of the name:
{name:"Joe"
,roles:...
How to convert an enum type variable to a string?
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There really is no beautiful way of doing this. Just set up an array of strings indexed by the enum.
If you do a lot of output, you can define an operator<< that takes an enum parameter and does the lookup for you.
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Understanding typedefs for function pointers in C
...es' code which had typedefs for pointers to functions with arguments. I recall that it took me a while to get around to such a definition while trying to understand a numerical algorithm written in C a while ago. So, could you share your tips and thoughts on how to write good typedefs for pointers t...
List of special characters for SQL LIKE clause
What is the complete list of all special characters for a SQL (I'm interested in SQL Server but other's would be good too) LIKE clause?
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How to read and write INI file with Python3?
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The standard ConfigParser normally requires access via config['section_name']['key'], which is no fun. A little modification can deliver attribute access:
class AttrDict(dict):
def __init__(self, *args, **kwargs):
super(AttrDict, self).__init...
C++ multiline string literal
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const char *text2 =
"Here, on the other hand, I've gone crazy \
and really let the literal span several lines, \
without bothering with quoting each line's \
content. This works, but you can't indent.";
Again, note those backslashes at the end of each line, they must be immediately before the...
How do I list the symbols in a .so file
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Note that readelf -Ws will show you all symbols, and nm -g shows only the externally visible symbols. This may be confusing if you are examining multiple symbol files and start interchanging your commands.
– Andrew B
May 2...
Should you always favor xrange() over range()?
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For performance, especially when you're iterating over a large range, xrange() is usually better. However, there are still a few cases why you might prefer range():
In python 3, range() does what xrange() used to do and xrange() does not exist. ...
Why doesn't django's model.save() call full_clean()?
...t curious if anyone knows if there's good reason why django's orm doesn't call 'full_clean' on a model unless it is being saved as part of a model form.
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Delete column from pandas DataFrame
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This answer isn't really correct - the pandas developers didn't, but that doesn't mean it is hard to do.
– wizzwizz4
Sep 30 '17 at 9:42
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