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How to format a java.sql Timestamp for displaying?
...er that if SimpleDateFormat object is a local-scoped object (it is created and used only inside a method), then it is thread-safe, since stack on which it will reside is inherently "thread-safe" (as it belongs to a single thread).
– quantum
Sep 13 '11 at 9:52
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Can existing virtualenv be upgraded gracefully?
I have a virtualenv created for Python 2.5 and want to "upgrade" it to Python 2.6.
5 Answers
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Get the current year in JavaScript
...
Create a new Date() object and call getFullYear():
new Date().getFullYear()
// returns the current year
Hijacking the accepted answer to provide some basic example context like a footer that always shows the current year:
<footer>
&...
surface plots in matplotlib
...ing projection='3d' in add_subplot
import matplotlib.pyplot as plt
import random
def fun(x, y):
return x**2 + y
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
x = y = np.arange(-3.0, 3.0, 0.05)
X, Y = np.meshgrid(x, y)
zs = np.array(fun(np.ravel(X), np.ravel(Y)))
Z = zs.reshape(...
Re-entrant locks in C#
...g on the same object. The recursive code effectively already has the lock and so can continue unhindered.
lock(object) {...} is shorthand for using the Monitor class. As Marc points out, Monitor allows re-entrancy, so repeated attempts to lock on an object on which the current thread already has ...
Wrapping a C library in Python: C, Cython or ctypes?
...Python application. I don't want to wrap the whole API, only the functions and datatypes that are relevant to my case. As I see it, I have three choices:
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Which characters are valid in CSS class names/selectors?
...racter is a hyphen, the second character must2 be a letter or underscore, and the name must be at least 2 characters long.
-?[_a-zA-Z]+[_a-zA-Z0-9-]*
In short, the previous rule translates to the following, extracted from the W3C spec.:
In CSS, identifiers (including element names, classes, ...
How to check if an array field contains a unique value or another array in MongoDB?
...n the help: mongodb.org/display/DOCS/…
– Scott Hernandez
Mar 20 '11 at 4:31
2
for the $all does...
How to get the browser viewport dimensions?
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Cross-browser @media (width) and @media (height) values
const vw = Math.max(document.documentElement.clientWidth || 0, window.innerWidth || 0)
const vh = Math.max(document.documentElement.clientHeight || 0, window.innerHeight || 0)
window.innerWidth a...
What is the C++ function to raise a number to a power?
...oesn't know which of float, double, or long double version it should take, and you would get an ambiguity error. All three would need a conversion from int to floating point, and all three are equally costly!
Therefore, be sure to have the first argument typed so it matches one of those three perf...