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How do I correctly clean up a Python object?
...it close() statement is that you have to worry about people forgetting to call it at all or forgetting to place it in a finally block to prevent a resource leak when an exception occurs.
To use the with statement, create a class with the following methods:
def __enter__(self)
def __exit__(self...
Python __str__ and lists
In Java, if I call List.toString(), it will automatically call the toString() method on each object inside the List. For example, if my list contains objects o1, o2, and o3, list.toString() would look something like this:
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Python hashable dicts
...n algol-like language (as apposed to the syntax free lisp dialects you normally find them in). Because of this, different passes through the input might see different grammars, so cached parse results are invalid, unless I also store the current version of the grammar along with the cached parse re...
What are 'get' and 'set' in Swift?
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That's actually explained right before the code:
In addition to simple properties that are stored, properties can have a getter and a setter.
class EquilateralTriangle: NamedShape {
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When some other class wants to get that pe...
sql “LIKE” equivalent in django query
...s. I have made the lookup into a Django-like-lookup application. After installing it the __like lookup with the % and _ wildcards will be enabled.
All the necessary code in the application is:
from django.db.models import Lookup
from django.db.models.fields import Field
@Field.register_lookup
cl...
Why is parenthesis in print voluntary in Python 2.7?
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In Python 2.x print is actually a special statement and not a function*.
This is also why it can't be used like: lambda x: print x
Note that (expr) does not create a Tuple (it results in expr), but , does. This likely results in the confusion between...
How do I remove a property from a JavaScript object?
...t object, then that object will, of course, not be garbage collected until all references to it have disappeared.
delete will only work on properties whose descriptor marks them as configurable.
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std::function and std::bind: what are they, and when should they be used?
...nd to get g:
auto g = bind(f, _1, 4, _2);
This is more concise than actually writing a functor class to do it.
There are further examples in the article you link to. You generally use it when you need to pass a functor to some algorithm. You have a function or functor that almost does the job yo...
How to use if - else structure in a batch file?
...stion about if - else structure in a batch file. Each command runs individually, but I couldn't use "if - else" blocks safely so these parts of my programme doesn't work. How can I do make these parts run? Thank you.
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Python memory leaks [closed]
... have a long-running script which, if let to run long enough, will consume all the memory on my system.
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