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Why is “if not someobj:” better than “if someobj == None:” in Python?
...
In the first test, Python try to convert the object to a bool value if it is not already one. Roughly, we are asking the object : are you meaningful or not ? This is done using the following algorithm :
If the object has a __nonzero__ s...
How do I seed a random class to avoid getting duplicate random values [duplicate]
...tes a sequence of numbers that adequately satisfies statistical randomness tests. Since the algorithm is deterministic, the algorithm will always generate the exact same sequence of numbers if it's initialized with the same seed. That's why system time (something that changes all the time) is usuall...
How to find patterns across multiple lines using grep?
...of the modern Linux systems can be used as
pcregrep -M 'abc.*(\n|.)*efg' test.txt
where -M, --multiline allow patterns to match more than one line
There is a newer pcre2grep also. Both are provided by the PCRE project.
pcre2grep is available for Mac OS X via Mac Ports as part of port pcre2:
...
What is the fastest method for selecting descendant elements in jQuery?
...parent').filter('.child') respectively.
So method 3 will always be the fastest because it needs to do the least amount of work and uses the most direct method to get first-level children.
Based on Anurag's revised speed tests here: http://jsfiddle.net/QLV9y/1/
Speed test: (More is Better)
On Chr...
Advantage of switch over if-else statement
...different area of the code, but now you have the opportunity to reuse this test. You also have more options for how to solve it. You could use std::set, for example:
bool RequiresSpecialEvent(int numError)
{
return specialSet.find(numError) != specialSet.end();
}
I'm not suggesting that thi...
Detect if stdin is a terminal or pipe?
... methods that can be used if different degrees of interactivity have to be tested.
Methods in Detail
There are several methods to detect if a program is running interactively.
Following table shows an overview:
cmd\method ctermid open isatty fstat
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How do I use spaces in the Command Prompt?
...y case: python ""C:\Program Files (x86)\Jenkins\workspace\Map Checker Unit Test\sqs-poller\node_modules\map-checker\python\unit_test.py" -d "C:\Program Files (x86)\Jenkins\workspace\Map Checker Unit Test\MAP_CHECK_TMP\#Test Case" -o "C:\Program Files (x86)\Jenkins\workspace\Map Checker Unit Test\MAP...
What is “assert” in JavaScript?
...sertion checking. Usually assertions (as they're called) are used only in "testing" or "debug" builds and stripped out of production code.
Suppose you had a function that was supposed to always accept a string. You'd want to know if someone called that function with something that wasn't a string. ...
Difference between rake db:migrate db:reset and db:schema:load
...ironment. If RAILS_ENV is not specified it defaults to the development and test databases.
db:create:all - Creates the database for all environments.
db:drop - Drops the database for the current RAILS_ENV environment. If RAILS_ENV is not specified it defaults to the development and test databases....
Find size of object instance in bytes in c#
... Marshal.ReadInt32(type.TypeHandle.Value, 4) works for x86 and x64. I only tested struct and class types. Keep in mind that this returns the boxed size for value types. @Pavel Maybe you could update your answer.
– jnm2
Mar 1 '15 at 1:52
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