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Check if value already exists within list of dictionaries?
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Here's one way to do it:
if not any(d['main_color'] == 'red' for d in a):
# does not exist
The part in parentheses is a generator expression that returns True for each dictionary that has the key-value pair you are looking for, otherwise False.
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ASP.NET MVC - Attaching an entity of type 'MODELNAME' failed because another entity of the same type
...wn during POSTing wrapper model and changing the state of one entry to 'Modified'. Before changing the state, the state is set to 'Detached' but calling Attach() does throw the same error. I'm using EF6.
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HTML if image is not found
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If Default.jpg is not available you will end up in an endless loop. You should add a check if (this.src != 'Default.jpg')
– dehlen
Jul 7 '16 at 10:05
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Is Meyers' implementation of the Singleton pattern thread safe?
...11, it is thread safe. According to the standard, §6.7 [stmt.dcl] p4:
If control enters
the declaration concurrently while the variable is being initialized, the concurrent execution shall wait for completion of the initialization.
GCC and VS support for the feature (Dynamic Initialization ...
Which cryptographic hash function should I choose?
The .NET framework ships with 6 different hashing algorithms:
9 Answers
9
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Why both no-cache and no-store should be used in HTTP response?
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I must clarify that no-cache does not mean do not cache. In fact, it means "revalidate with server" before using any cached response you may have, on every request.
must-revalidate, on the other hand, only needs to revalidate when the ...
Extract filename and extension in Bash
...ocus on the last '/' of the path instead of the '.' which should work even if you have unpredictable file extensions:
filename="${fullfile##*/}"
You may want to check the documentation :
On the web at section "3.5.3 Shell Parameter Expansion"
In the bash manpage at section called "Parameter Exp...
Getting reference to the top-most view/window in iOS application
I'm creating a reusable framework for displaying notifications in an iOS application. I'd like the notification views to be added over the top of everything else in the application, sort of like a UIAlertView. When I init the manager that listens for NSNotification events and adds views in response,...
Android - Package Name convention
... having it in reverse order is to do with the layout on the storage media. If you consider each period ('.') in the application name as a path separator, all applications from a publisher would sit together in the path hierarchy.
So, for instance, packages from Adobe would be of the form:
com.adobe...
log messages appearing twice with Python Logging
...oy) : getLogger will return the same object, but addHandler does not check if a similar handler has already been added to the logger.
Try tracing calls to that method and eliminating one of these. Or set up a flag logging_initialized initialized to False in the __init__ method of Boy and change co...