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How to check 'undefined' value in jQuery
... variable or other unevaluated operand. The main advantage of this method, compared to if (value === undefined) { ... }, is that typeof will never raise an exception in case if variable value does not exist.
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Find out time it took for a python script to complete execution
...test function"
L = []
for i in range(100):
L.append(i)
if __name__=='__main__':
from timeit import Timer
t = Timer("test()", "from __main__ import test")
print t.timeit()
Then to convert to minutes, you can simply divide by 60. If you want the script runtime in an easi...
Rename Files and Directories (Add Prefix)
...ll work for filenames with spaces in them:
for f in * ; do mv -- "$f" "PRE_$f" ; done
("--" is needed to succeed with files that begin with dashes, whose names would otherwise be interpreted as switches for the mv command)
...
How to log source file name and line number in Python
...='%Y-%m-%d:%H:%M:%S',
level=logging.DEBUG)
logger = logging.getLogger(__name__)
logger.debug("This is a debug log")
logger.info("This is an info log")
logger.critical("This is critical")
logger.error("An error occurred")
Generates this output:
2017-06-06:17:07:02,158 DEBUG [log.py:11] Thi...
How does “cat
...
This is called heredoc format to provide a string into stdin. See https://en.wikipedia.org/wiki/Here_document#Unix_shells for more details.
From man bash:
Here Documents
This type of redirection instructs the shell to read input from
the current source until a line
containin...
javascript: pause setTimeout();
...
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Add a new column to existing table in a migration
...lashing with existing models
for Laravel 3:
php artisan migrate:make add_paid_to_users
for Laravel 5+:
php artisan make:migration add_paid_to_users_table --table=users
You then need to use the Schema::table() method (as you're accessing an existing table, not creating a new one). And you ca...
How do I add the contents of an iterable to a set?
...
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Makefile经典教程（入门必备） - C/C++ - 清泛网 - 专注IT技能提升
...的话，相信大家对这个人并不比我陌生，这是他的主页：http://www.stallman.org/ 。
第二位是：Roland McGrath
个人主页是：http://www.frob.com/~roland/ ，下面是他的一些事迹：
1） 合作编写了并维护GNU make。
2） 和Thomas ...