Non-Java Language

In Cats-effect, when is xxx inside IO.pure(xxx) executed?

It’s said IO.pure() means eager evaluation. But it doesn’t seem to so in this example: Here println(“print in pure”) is executed just like as if it’s IO.apply() Another example, however, discloses the truth Here is it how it works: When printTwice() is called, every expression inside it is evaluated IO.apply(println(“print in lazy”)) is evaluated as …

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Python: PIL generates an image too big?

You’ve tried thumbnail(), resize(), save(quality=20),  but you still get an image too big? Maybe it’s because you are generating a PNG file.  Change it to JPG and you will get a much smaller file ! It’s because PNG format is a lossless compression file format.  Without losing quality you can’t get a considerably small image …

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Let Django’s migration run raw SQL

You’ve created a new column and you want set its value as the "id" column. What to do?  Add the following line to the generated migration file or you can create new migration file migrations.RunSQL(sql=”update some_table set new_column = id”)

man.get_things() or Thing.get_things_by_man() when Active Records Pattern is used?

There is requirement for a method to get things of a man.  Where to put it?   man.get_things() or   (static) Thing.get_things_by_man()  ?   From OO’s perspective, the former sounds more natural.   I was planning to adopt this approach until I found a problem:  it may lead to duplicate db access code because not …

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codeIgniter默认情况下关闭浏览器不会使session过期

codeIgniter默认情况下关闭浏览器不会使session过期。也就是说,如果你没有显式登出而只是关闭浏览器,在一定时间内(codeIgniter默认是2小时)打开浏览器重新访问这个网站,会发现你仍处于登录状态。 为了规避这个风险,应该 //config.php $config[‘sess_expire_on_close’] = TRUE;