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The Definitive C++ Book Guide and List
...iki nature. The project documents all versions of the C++ standard and the site allows filtering the display for a specific version. The project was presented by Nate Kohl at CppCon'14.
Classics / Older
Note: Some information contained within these books may not be up-to-date or no longer conside...
How can I make a horizontal ListView in Android? [duplicate]
...) There is no recycling of views. Maybe it would be possible to tack this functionality onto the scroll view, but it seems to me that it would mess with the scrolling behavior, and it would be nearly as much work as simply extending AdapterView.
– Neil Traft
O...
Play sound on button click android
...
mp = MediaPlayer.create(context, R.raw.sound_two);
and play it !
Have fun!
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How to add google chrome omnibox-search support for your site?
...e in it "Press TAB to search in $URL". For example, there are some russian sites habrahabr.ru or yandex.ru. When you press TAB you'll be able to search in that site, not in your search engine.
How to make my site to be able for it? Maybe, I need to write some special code in my site pages?
...
Remove duplicated rows using dplyr
...ction for this purpose.
Original answer below:
library(dplyr)
set.seed(123)
df <- data.frame(
x = sample(0:1, 10, replace = T),
y = sample(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_nu...
What does “where T : class, new()” mean?
...gt;
where T : class, new()
{
}
class Checks
{
INewable<int> cn1; // ALLOWED: has parameterless ctor
INewable<string> n2; // NOT ALLOWED: no parameterless ctor
INewable<MyStruct> n3; // ALLOWED: has parameterless ctor
INewable<MyClass1> n4; // ALLOWED: has...
Checking if a string can be converted to float in Python
... ------------
print(isfloat("")) False
print(isfloat("1234567")) True
print(isfloat("NaN")) True nan is also float
print(isfloat("NaNananana BATMAN")) False
print(isfloat("123.456")) True
print(isfloat("123.E4")) ...
Which version of Python do I have installed?
...ons are installed:
updatedb # Be in root for this
locate site.py # All installations I've ever seen have this
The output for a single Python installation should look something like this:
/usr/lib64/python2.7/site.py
/usr/lib64/python2.7/site.pyc
/usr/lib64/python2.7/s...
What does the “yield” keyword do?
...one, etc. And generators return... well that's where yield comes in:
def f123():
yield 1
yield 2
yield 3
for item in f123():
print item
Instead of yield statements, if you had three return statements in f123() only the first would get executed, and the function would exit. But f1...
Dynamic SQL - EXEC(@SQL) versus EXEC SP_EXECUTESQL(@SQL)
...
EXEC('SELECT * FROM FOO WHERE ID=?', 123) will replace the parameter placeholder "?" with the value 123 and then execute the query, returning a result for SELECT * FROM FOO WHERE ID=123
– Peter Wone
Jun 1 '10 at 23:27
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