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Int division: Why is the result of 1/3 == 0?
...se returns the true result of division rounded towards zero. The result of 0.333... is thus rounded down to 0 here. (Note that the processor doesn't actually do any rounding, but you can think of it that way still.)
Also, note that if both operands (numbers) are given as floats; 3.0 and 1.0, or eve...
Split a String into an array in Swift?
... like so:
var fullName = "First Last"
var fullNameArr = split(fullName) {$0 == " "}
var firstName: String = fullNameArr[0]
var lastName: String? = fullNameArr.count > 1 ? fullNameArr[1] : nil
with Swift 2
In Swift 2 the use of split becomes a bit more complicated due to the introduction of t...
Standard deviation of a list
...
Since Python 3.4 / PEP450 there is a statistics module in the standard library, which has a method stdev for calculating the standard deviation of iterables like yours:
>>> A_rank = [0.8, 0.4, 1.2, 3.7, 2.6, 5.8]
>>> import statis...
UIView Hide/Show with animation
...
Objective C
[UIView transitionWithView:button
duration:0.4
options:UIViewAnimationOptionTransitionCrossDissolve
animations:^{
button.hidden = YES;
}
completion:NULL];
Swift
UIView.transitio...
Python matplotlib multiple bars
...lotlib.dates import date2num
import datetime
x = [
datetime.datetime(2011, 1, 4, 0, 0),
datetime.datetime(2011, 1, 5, 0, 0),
datetime.datetime(2011, 1, 6, 0, 0)
]
x = date2num(x)
y = [4, 9, 2]
z = [1, 2, 3]
k = [11, 12, 13]
ax = plt.subplot(111)
ax.bar(x-0.2, y, width=0.2, color='b', ...
Pandas get topmost n records within each group
...
>>> df.groupby('id').head(2)
id value
id
1 0 1 1
1 1 2
2 3 2 1
4 2 2
3 7 3 1
4 8 4 1
(Keep in mind that you might need to order/sort before, depending on your data)
EDIT: As mentioned by the questioner, use df.gro...
Can I add jars to maven 2 build classpath without installing them?
...
605
Problems of popular approaches
Most of the answers you'll find around the internet will suggest...
Nested JSON objects - do I have to use arrays for everything?
...
204
You don't need to use arrays.
JSON values can be arrays, objects, or primitives (numbers or st...
How do android screen coordinates work?
...t maxX= mdisp.getWidth();
int maxY= mdisp.getHeight();
(x,y) :-
1) (0,0) is top left corner.
2) (maxX,0) is top right corner
3) (0,maxY) is bottom left corner
4) (maxX,maxY) is bottom right corner
here maxX and maxY are screen maximum height and width in pixels, which we have retrieved i...
How to properly assert that an exception gets raised in pytest?
...est_passes():
with pytest.raises(Exception) as e_info:
x = 1 / 0
def test_passes_without_info():
with pytest.raises(Exception):
x = 1 / 0
def test_fails():
with pytest.raises(Exception) as e_info:
x = 1 / 1
def test_fails_without_info():
with pytest.raises(...