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Accessing class variables from a list comprehension in the class definition
...owing will fail:
class A:
a = 42
b = list(a + i for i in range(10))
So, to summarize: you cannot access the class scope from functions, list comprehensions or generator expressions enclosed in that scope; they act as if that scope does not exist. In Python 2, list comprehensions were i...
Too many 'if' statements?
...
600
If you cannot come up with a formula, you can use a table for such a limited number of outcomes...
How does numpy.histogram() work?
...qual width) of each bar.
In this example:
np.histogram([1, 2, 1], bins=[0, 1, 2, 3])
There are 3 bins, for values ranging from 0 to 1 (excl 1.), 1 to 2 (excl. 2) and 2 to 3 (incl. 3), respectively. The way Numpy defines these bins if by giving a list of delimiters ([0, 1, 2, 3]) in this example...
[] and {} vs list() and dict(), which is better?
...s/dicts:
>>> from timeit import timeit
>>> timeit("[]")
0.040084982867934334
>>> timeit("list()")
0.17704233359267718
>>> timeit("{}")
0.033620194745424214
>>> timeit("dict()")
0.1821558326547077
and for non-empty:
>>> timeit("[1,2,3]")
0.243...
Sort array of objects by single key with date value
... use Array.sort.
Here's an example:
var arr = [{
"updated_at": "2012-01-01T06:25:24Z",
"foo": "bar"
},
{
"updated_at": "2012-01-09T11:25:13Z",
"foo": "bar"
},
{
"updated_at": "2012-01-05T04:13:24Z",
"foo": "bar"
}
]
arr.sort(function(a, b) {
v...
Adding an arbitrary line to a matplotlib plot in ipython notebook
...as np
import matplotlib.pyplot as plt
np.random.seed(5)
x = np.arange(1, 101)
y = 20 + 3 * x + np.random.normal(0, 60, 100)
plt.plot(x, y, "o")
# draw vertical line from (70,100) to (70, 250)
plt.plot([70, 70], [100, 250], 'k-', lw=2)
# draw diagonal line from (70, 90) to (90, 200)
plt.plot([70,...
How to connect to Mysql Server inside VirtualBox Vagrant?
... can I connect to that server outside the vm? I already forward the port 3306 of the Vagrantfile , but when I try to connect to the mysql server, it`s resposts with the error:
'reading initial communication packet'
...
How to run a background task in a servlet based web application?
...ples:
@Singleton
public class BackgroundJobManager {
@Schedule(hour="0", minute="0", second="0", persistent=false)
public void someDailyJob() {
// Do your job here which should run every start of day.
}
@Schedule(hour="*/1", minute="0", second="0", persistent=false)
pu...
Use find command but exclude files in two directories
... it happy.
– peelman
Nov 12 '13 at 20:08
3
...
How do I get time of a Python program's execution?
...s that your program takes at least a tenth of second to run.
Prints:
--- 0.764891862869 seconds ---
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