大约有 45,000 项符合查询结果(耗时:0.0602秒) [XML]

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Run a callback only if an attribute has changed in Rails

...saving to the database, or within the before_save filter: changes should now be changes_to_save changed? should now be has_changes_to_save? changed should now be changed_attribute_names_to_save <attribute>_change should now be <attribute>_change_to_be_saved <attribute>_changed? s...
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Why shouldn't I use mysql_* functions in PHP?

...jan Marjanovic will help you to choose. And a better way is PDO, and I am now writing a simple PDO tutorial. A simple and short PDO tutorial Q. First question in my mind was: what is `PDO`? A. “PDO – PHP Data Objects – is a database access layer providing a uniform method of access to ...
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Pointers in Python?

I know Python doesn't have pointers, but is there a way to have this yield 2 instead 9 Answers ...
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How to “properly” create a custom object in JavaScript?

...ype.toString= function() { return 'Shape at '+this.x+', '+this.y; }; Now to subclass it, in as much as you can call what JavaScript does subclassing. We do that by completely replacing that weird magic prototype property: function Circle(x, y, r) { Shape.call(this, x, y); // invoke the ba...
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List directory tree structure in python?

I know that we can use os.walk() to list all sub-directories or all files in a directory. However, I would like to list the full directory tree content: ...
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ipython reads wrong python version

...'ll be /usr/local/bin/ipython. Let's look inside: Edit 9/7/16 -- The file now looks like this: cat /usr/local/bin/ipython #!/usr/bin/python # -*- coding: utf-8 -*- import re import sys from IPython import start_ipython if __name__ == '__main__': sys.argv[0] = re.sub(r'(-script\.pyw|\.exe)?...
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What is the formal difference in Scala between braces and parentheses, and when should they be used?

...+ _) // invalid, A* vararg parameter However, there’s more you need to know to better grasp these rules. Increased compile checking with parens The authors of Spray recommend round parens because they give increased compile checking. This is especially important for DSLs like Spray. By using pa...
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What is the documents directory (NSDocumentDirectory)?

...ch with @"~/Documents". Hardcoding paths is never a good idea. It may work now, but if Apple ever chooses to rename or move the Documents directory, your app will break. NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); will always give you the correct directory! ...
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Recommendations of Python REST (web services) framework? [closed]

...on-based views and CherryPy's default dispatcher, although both frameworks now provide a way around this problem (class-based views and MethodDispatcher, respectively). HTTP-verbs are very important in REST, and unless you're very careful about this, you'll end up falling into a REST anti-pattern. ...
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What's the pythonic way to use getters and setters?

...ute # @attribute.setter # the property decorates with `.setter` now def attribute(self, value): # name, e.g. "attribute", is the same self._attribute = value # the "value" name isn't special # @attribute.deleter # decorate with `.deleter` def attribute(self...