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C++ equivalent of java's instanceof
...e of course).
As pointed out dynamic_cast doesn't come for free. A simple and consistently performing hack that handles most (but not all cases) is basically adding an enum representing all the possible types your class can have and check whether you got the right one.
if(old->getType() == BOX...
TypeError: 'NoneType' object is not iterable in Python
...al life other than making us insert few ugly if data is not None: kind of handling.
– nehem
Sep 1 '17 at 6:59
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“Single-page” JS websites and SEO
...ys. In my opinion, this is done right by letting the server act as an API (and nothing more) and letting the client handle all of the HTML generation stuff. The problem with this "pattern" is the lack of search engine support. I can think of two solutions:
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Visual Studio Clicking Find Results Opens Code in Wrong Window
I'm using Visual Studio 2010 and when I do a "Find in Files" the results are returned to the "Find Results 1" window which is docked below my code editor window.
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How to check task status in Celery?
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Return the task_id (which is given from .delay()) and ask the celery instance afterwards about the state:
x = method.delay(1,2)
print x.task_id
When asking, get a new AsyncResult using this task_id:
from celery.result import AsyncResult
res = AsyncResult("your-task-id")
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How to allow to accept only image files?
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Use the accept attribute of the input tag. So to accept only PNGs, JPEGs and GIFs you can use the following code:
<input type="file" name="myImage" accept="image/x-png,image/gif,image/jpeg" />
Or simply:
<input type="file" name="myImage" accept="image/*" />
Note...
Xcode 6 how to enable storyboard zoom?
I've updated to Xcode 6 beta 3 and see that the [+ = -] buttons in the storyboard corner are gone. Is there a way for me to zoom in and out on view controllers within a storyboard in Xcode 6?
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Accessing private member variables from prototype-defined functions
...efined on a prototype are not defined within the scope of the constructor, and will not have access to the constructor's local variables.
You can still have private variables, but if you want methods defined on the prototype to have access to them, you should define getters and setters on the this ...
Ruby custom error classes: inheritance of the message attribute
... you don't have to pass it to the constructor:
class MyCustomError < StandardError
attr_reader :object
def initialize(object)
@object = object
end
end
begin
raise MyCustomError.new("an object"), "a message"
rescue MyCustomError => e
puts e.message # => "a message"
puts e....
Removing index column in pandas when reading a csv
I have the following code which imports a CSV file. There are 3 columns and I want to set the first two of them to variables. When I set the second column to the variable "efficiency" the index column is also tacked on. How can I get rid of the index column?
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