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Doing something before program exit
...int a message when my application was terminating:
import atexit
def exit_handler():
print 'My application is ending!'
atexit.register(exit_handler)
Just be aware that this works great for normal termination of the script, but it won't get called in all cases (e.g. fatal internal errors).
...
Rspec doesn't see my model Class. uninitialized constant error
...
Your spec_helper file is missing some important commands. Specifically, it's not including config/environment and initializing rspec-rails.
You can add the following lines to the start of your spec/spec_helper.rb file
ENV["RAILS_EN...
Python Pandas: Get index of rows which column matches certain value
...tion and then create slices for use in iloc(). The only thing I see is get_loc, but it cannot take an array.
– sheridp
Apr 21 '16 at 0:47
3
...
What is Func, how and when is it used
...PrintListToConsole<T> {
private PrintListConsoleRender<T> _renderer;
public void SetRenderer(PrintListConsoleRender<T> r) {
// this is the point where I can personalize the render mechanism
_renderer = r;
}
public void PrintToConsole(List<T>...
JavaScript is in array
...if the result > -1 and false if result === -1
– bm_i
Nov 5 '12 at 19:01
11
@bm_i Which faster?...
Ways to implement data versioning in MongoDB
...nt contain a dictionary of time-stamped diffs. Something like this:
{
_id : "id of address book record",
changes : {
1234567 : { "city" : "Omaha", "state" : "Nebraska" },
1234568 : { "city" : "Kansas City", "state" : "Missouri" }
}
}
To make...
Is there a way to detach matplotlib plots so that the computation can continue?
...rocessing import Process
from matplotlib.pyplot import plot, show
def plot_graph(*args):
for data in args:
plot(data)
show()
p = Process(target=plot_graph, args=([1, 2, 3],))
p.start()
print 'yay'
print 'computation continues...'
print 'that rocks.'
print 'Now lets wait for the g...
C++ equivalent of java's instanceof
...
Try using:
if(NewType* v = dynamic_cast<NewType*>(old)) {
// old was safely casted to NewType
v->doSomething();
}
This requires your compiler to have rtti support enabled.
EDIT:
I've had some good comments on this answer!
Every time you nee...
Getting a map() to return a list in Python 3.x
...o be ASCII/latin-1 is to do bulk conversions at the C layer: bytes(sequence_of_ints_in_range_0_to_256).decode('latin-1') which makes a str faster by avoiding Python function calls for each element in favor of a bulk conversion of all elements using only C level function calls. You can wrap the above...
Add Foreign Key to existing table
...
To add a foreign key (grade_id) to an existing table (users), follow the following steps:
ALTER TABLE users ADD grade_id SMALLINT UNSIGNED NOT NULL DEFAULT 0;
ALTER TABLE users ADD CONSTRAINT fk_grade_id FOREIGN KEY (grade_id) REFERENCES grades(id);
...