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Event system in Python

...r methods', which is a simple implementation of the Observer pattern. Basically, the handler methods (callables) are stored in an array and are each called when the event 'fires'. Publish-Subscribe The disadvantage of Observer event systems is that you can only register the handlers on the actual Ev...
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mysql -> insert into tbl (select from another table) and some default values [duplicate]

... If you want to insert all the columns then insert into def select * from abc; here the number of columns in def should be equal to abc. if you want to insert the subsets of columns then insert into def (col1,col2, col3 ) select scol1,scol2,...
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Wrap a delegate in an IEqualityComparer

...fying. But I still don't understand your hashing policy of t => 0. If all objects always hash to the same thing (zero), then isn't that even more broken than using obj.GetHashCode, per @Dan Tao's point? Why not always force the caller to provide a good hash function? – Jo...
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Test if a variable is a list or tuple

... excludes custom sequences, iterators, and other things that you might actually need. However, sometimes you need to behave differently if someone, for instance, passes a string. My preference there would be to explicitly check for str or unicode like so: import types isinstance(var, types.String...
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How to track down a “double free or corruption” error

... If you're using glibc, you can set the MALLOC_CHECK_ environment variable to 2, this will cause glibc to use an error tolerant version of malloc, which will cause your program to abort at the point where the double free is done. You can set this from gdb by using ...
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How to remove an item from an array in AngularJS scope?

... Your issue is not really with Angular, but with Array methods. The proper way to remove a particularly item from an array is with Array.splice. Also, when using ng-repeat, you have access to the special $index property, which is the current inde...
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How to add Google Analytics Tracking ID to GitHub Pages

... I have added them, however Google analytics say the Tracking is not installed. My page as specified in G-Analytics is http://avi-aryan.github.io – Avi Jul 15 '13 at 12:33 1 ...
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What is the difference between 'my' and 'our' in Perl?

... On the other hand, our variables are package variables, and thus automatically: global variables definitely not private not necessarily new can be accessed outside the package (or lexical scope) with the qualified namespace, as $package_name::variable. Declaring a variable with our allows you...
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How to take the first N items from a generator or list in Python? [duplicate]

...imple syntax: array[start:stop:step] You can omit any parameter. These are all valid: array[start:], array[:stop], array[::step] Slicing a generator import itertools top5 = itertools.islice(my_list, 5) # grab the first five elements You can't slice a generator directly in Python. itertools.i...
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Efficiently updating database using SQLAlchemy ORM

...ngs in mind when using the ORM and plain SQL in the same transaction. Basically, from one side, ORM data modifications will only hit the database when you flush the changes from your session. From the other side, SQL data manipulation statements don't affect the objects that are in your session. So...