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Find integer index of rows with NaN in pandas dataframe
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add .to_numpy() to convert in numpy array first - pd.isnull(df).any(1).to_numpy().nonzero()
– 7bStan
Nov 6 '19 at 7:21
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Is there a Python function to determine which quarter of the year a date is in?
...y to check for yourself what formula is right:
for m in range(1, 13):
print m//4 + 1,
print
gives 1 1 1 2 2 2 2 3 3 3 3 4 -- two four-month quarters and a single-month one (eep).
for m in range(1, 13):
print (m-1)//3 + 1,
print
gives 1 1 1 2 2 2 3 3 3 4 4 4 -- now doesn't this look vastly ...
fastest (low latency) method for Inter Process Communication between Java and C/C++
...actly 0.1 microsecond, while doing a primitive string concatenation only:
int j=123456789;
String ret = "my-record-key-" + j + "-in-db";
P.P.P.S - hope this is not too much off-topic, but finally I tried replacing Thread.sleep(0) with incrementing a static volatile int variable (JVM happens to f...
Passing A List Of Objects Into An MVC Controller Method Using jQuery Ajax
I'm trying to pass an array of objects into an MVC controller method using
jQuery's ajax() function. When I get into the PassThing() C# controller method,
the argument "things" is null. I've tried this using a type of List for
the argument, but that doesn't work either. What am I doing wrong?
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Is it intended by the C++ standards committee that in C++11 unordered_map destroys what it inserts?
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As others have pointed out in the comments, the "universal" constructor is not, in fact, supposed to always move from its argument. It's supposed to move if the argument is really an rvalue, and copy if it's an lvalue.
The behaviour, you obs...
Difference between StringBuilder and StringBuffer
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and StringBuilder is intended as a drop in replacement for StringBuffer where synchronisation is not required
– Joel
Dec 23 '09 at 8:52
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ASP.NET MVC controller actions that return JSON or partial html
...getJSON function. You can call the
public ActionResult SomeActionMethod(int id)
{
return Json(new {foo="bar", baz="Blech"});
}
Method from the jquery getJSON method by simply...
$.getJSON("../SomeActionMethod", { id: someId },
function(data) {
alert(data.foo);
alert(d...
How to set a timer in android
... on the context. The docs on AlarmManager say, "Note: The Alarm Manager is intended for cases where you want to have your application code run at a specific time, even if your application is not currently running. For normal timing operations (ticks, timeouts, etc) it is easier and much more efficie...
Knight's Shortest Path on Chessboard
...d be like:
(a1,b3)=1,
(a1,c2)=1,
.....
And the shortest path of two points in a graph can be found using http://en.wikipedia.org/wiki/Dijkstra's_algorithm
Pseudo-code from wikipedia-page:
function Dijkstra(Graph, source):
for each vertex v in Graph: // Initializations
dist...
NumPy array initialization (fill with identical values)
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NumPy 1.8 introduced np.full(), which is a more direct method than empty() followed by fill() for creating an array filled with a certain value:
>>> np.full((3, 5), 7)
array([[ 7., 7., 7., 7., 7.],
[ 7., 7., 7., ...