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What is the __del__ method, How to call it?

... ends. In particular, unless there are circular references, CPython (the standard Python implementation) will garbage collect immediately. However, this is an implementation detail of CPython. The only required property of Python garbage collection is that it happens after all references have been...
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Why is pow(a, d, n) so much faster than a**d % n?

I was trying to implement a Miller-Rabin primality test , and was puzzled why it was taking so long (> 20 seconds) for midsize numbers (~7 digits). I eventually found the following line of code to be the source of the problem: ...
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Difference in months between two dates

...ssuming the day of the month is irrelevant (i.e. the diff between 2011.1.1 and 2010.12.31 is 1), with date1 > date2 giving a positive value and date2 > date1 a negative value ((date1.Year - date2.Year) * 12) + date1.Month - date2.Month Or, assuming you want an approximate number of 'average...
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GPL and LGPL open source licensing restrictions [closed]

I am having trouble understanding the usage permissions of open source. I read somewhere that GPL or LGPL enforces that software that uses GPL software must also be released open-source. I want to create an application that uses some open-source image recognition library. Can I sell this application...
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JPA: How to have one-to-many relation of the same Entity type

... Yes, this is possible. This is a special case of the standard bidirectional @ManyToOne/@OneToMany relationship. It is special because the entity on each end of the relationship is the same. The general case is detailed in Section 2.10.2 of the JPA 2.0 spec. Here's a worked exa...
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Center a map in d3 given a geoJSON object

... you have a geoJSON object that you are going to draw you have to scale it and translate it in order to get it to the size that one wants and translate it in order to center it. This is a very tedious task of trial and error, and I was wondering if anyone knew a better way to obtain these values? ...
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Do I need to close() both FileReader and BufferedReader?

...Reader.close() closes the stream according to javadoc for BufferedReader and InputStreamReader as well as FileReader.close() does. share | improve this answer | follow ...
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How to determine the current shell I'm working on

...t to actual shell name in csh or tcsh $ZSH_NAME is set on zsh ksh has $PS3 and $PS4 set, whereas the normal Bourne shell (sh) only has $PS1 and $PS2 set. This generally seems like the hardest to distinguish - the only difference in the entire set of environment variables between sh and ksh we have i...
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String literals: Where do they go?

...e string literals changeable (it will be highly dependent on your platform and could change over time), just use arrays: char foo[] = "..."; The compiler will arrange for the array to get initialized from the literal and you can modify the array. ...
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Transfer-Encoding: gzip vs. Content-Encoding: gzip

...er requests regarding that content (e.g., PUT or conditional GET) to be handled correctly. This is, of course, why performing on-the-fly content-encoding is a stupid idea, and why I added Transfer-Encoding to HTTP as the proper way to do on-the-fly encoding without changing the resource. ...