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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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Javascript - How to detect if document has loaded (IE 7/Firefox 3)
I want to call a function after a document loads, but the document may or may not have finished loading yet. If it did load, then I can just call the function. If it did NOT load, then I can attach an event listener. I can't add an eventlistener after onload has already fired since it won't get cal...
Getting Java version at runtime
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Wow, that kind of blew my mind. Though in my case, all I wanted was the first two parts of the version so: Runtime.class.getPackage().getSpecificationVersion()
– Wesley Hartford
Dec 10 '14 at 21:44
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MongoDB/NoSQL: Keeping Document Change History
... changes to one or more specific entities in a database. I've heard this called row versioning, a log table or a history table (I'm sure there are other names for it). There are a number of ways to approach it in an RDBMS--you can write all changes from all source tables to a single table (more of...
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:...
Python - Get path of root project structure
...to prevent directories with a common name, such as string, from unintentionally hiding valid modules that occur later on the module search path. In the simplest case, __init__.py can just be an empty file, but it can also execute initialization code for the package or set the __all__ variable, descr...
Access an arbitrary element in a dictionary in Python
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for a non-destructive popitem you can make a (shallow) copy: key, value = dict(d).popitem()
– Pelle
Jan 31 '18 at 10:35
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open read and close a file in 1 line of code
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You don't really have to close it - Python will do it automatically either during garbage collection or at program exit. But as @delnan noted, it's better practice to explicitly close it for various reasons.
So, what you can do to keep ...
How to increase the vertical split window size in Vim
:vsplit (short form: :vs ) split the Vim viewport vertically. :30vs splits the viewport, making the new window 30 characters wide. Once this 30 char window is created, how would one change it's size to 31 or 29?
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Query to list all stored procedures
What query can return the names of all the stored procedures in a SQL Server database
23 Answers
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