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String concatenation: concat() vs “+” operator

...then throwing it away when you create the final String. In practice memory allocation is surprisingly fast. Update: As Pawel Adamski notes, performance has changed in more recent HotSpot. javac still produces exactly the same code, but the bytecode compiler cheats. Simple testing entirely fails bec...
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How to pass a user defined argument in scrapy spider

... The above code is only partially working for me. For eg. If I define domain using self.domain, I'm still not able to access it outside the __init__ method. Python throws a not defined error. BTW, why have you omitted the super call? PS. I'm working wit...
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Dealing with float precision in Javascript [duplicate]

...of significant digits, like this: (Math.floor(y/x) * x).toFixed(2) Convert all your numbers to integers share | improve this answer | follow | ...
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PHP Get name of current directory

... libs/common.php That way when common.php is require'd in main.php, the call of require_once in common.php will correctly includes editor.php in images/editor.php instead of trying to look in current directory where main.php is run. ...
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How do I list the symbols in a .so file

... Note that readelf -Ws will show you all symbols, and nm -g shows only the externally visible symbols. This may be confusing if you are examining multiple symbol files and start interchanging your commands. – Andrew B May 2...
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How to join two JavaScript Objects, without using JQUERY [duplicate]

... merge them and crete a single json object. The resultant json should have all the values from obj2 and the values from obj1 which is not present in obj2. ...
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Can you give a Django app a verbose name for use throughout the admin?

...h to the appropriate AppConfig subclass to be configured explicitly in INSTALLED_APPS. Example: INSTALLED_APPS = [ # ...snip... 'yourapp.apps.YourAppConfig', ] Then alter your AppConfig as listed below. Django 1.7 As stated by rhunwicks' comment to OP, this is now possible out of the ...
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How can I save a screenshot directly to a file in Windows? [closed]

...ormat format = ImageFormat.PNG; or ImageFormat format = ImageFormat.JPG; All is here for you – Patrick Desjardins Oct 1 '08 at 15:31 4 ...
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Redirecting stdout to “nothing” in python

... A nice way to do this is to create a small context processor that you wrap your prints in. You then just use is in a with-statement to silence all output. Python 2: import os import sys from contextlib import contextmanager @contextmanager def silence_stdout(): ...
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Is there a decorator to simply cache function return values?

...maxsize=100, typed=False) Decorator to wrap a function with a memoizing callable that saves up to the maxsize most recent calls. It can save time when an expensive or I/O bound function is periodically called with the same arguments. Example of an LRU cache for computing Fibonacci numbers: @lru...