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What does Python's eval() do?
...less until you find a need for it. It is used on sites like codepad.org to allow you to execute scripts in a test environment. eval() can also be used to execute highly-dynamic code, but you should make yourself fully aware of the security and performance risks before using it.
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Filtering for empty or NULL names in a queryset
...lias (optional) which I need to search for. So, I need a query to give me all the names that have an alias set.
7 Answers
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What do I use for a max-heap implementation in Python?
... amazed that there IS such a built-in solution in heapq. But then it is totally unreasonable that it is NOT even slightly mentioned at all in the official document! WTF!
– RayLuo
Apr 21 '15 at 6:48
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Can I use __init__.py to define global variables?
I want to define a constant that should be available in all of the submodules of a package. I've thought that the best place would be in in the __init__.py file of the root package. But I don't know how to do this. Suppose I have a few subpackages and each with several modules. How can I access th...
How to decorate a class?
...2.5, is there a way to create a decorator that decorates a class? Specifically, I want to use a decorator to add a member to a class and change the constructor to take a value for that member.
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What is the meaning of single and double underscore before an object name?
...at least two leading underscores, at most one trailing underscore) is textually replaced with _classname__spam, where classname is the current class name with leading underscore(s) stripped. This mangling is done without regard to the syntactic position of the identifier, so it can be used to define...
How to force link from iframe to be opened in the parent window
...of the page in the iframe:
<base target="_parent">
This will load all links on the page in the parent window. If you want your links to load in a new window, use:
<base target="_blank">
This tag is fully supported in all browsers.
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Is there a decorator to simply cache function return values?
...maxsize=100, typed=False)
Decorator to wrap a function with a memoizing callable that saves up to the maxsize most recent calls. It can save time when an expensive or I/O bound function is periodically called with the same arguments.
Example of an LRU cache for computing Fibonacci numbers:
@lru...
Relative imports in Python 3
...ython3.
The simplest fix for this case, assuming the name mymodule is globally unique, would be to avoid using relative imports, and just use...
from mymodule import as_int
...although, if it's not unique, or your package structure is more complex, you'll need to include the directory containing...
C#: Printing all properties of an object [duplicate]
Is there a method built in to .NET that can write all the properties and such of an object to the console? Could make one using reflection of course, but I'm curious to if this already exists... especially since you can do it in Visual Studio in the Immediate Window. There you can an object name (wh...