大约有 37,000 项符合查询结果（耗时：0.0455秒） [XML]
Cast Object to Generic Type for returning
...rSpaceTrucker
11.2k55 gold badges4545 silver badges9090 bronze badges
59
...
pandas read_csv and filter columns with usecols
...andas as pd
from StringIO import StringIO
csv = r"""dummy,date,loc,x
bar,20090101,a,1
bar,20090102,a,3
bar,20090103,a,5
bar,20090101,b,1
bar,20090102,b,3
bar,20090103,b,5"""
df = pd.read_csv(StringIO(csv),
header=0,
index_col=["date", "loc"],
usecols=["date", "loc", "x"],
...
Clearing a string buffer/builder after loop
...ete method as follows:
StringBuffer sb = new StringBuffer();
for (int n = 0; n < 10; n++) {
sb.append("a");
// This will clear the buffer
sb.delete(0, sb.length());
}
Another option (bit cleaner) uses setLength(int len):
sb.setLength(0);
See Javadoc for more info:
...
dplyr: “Error in n(): function should not be called directly”
...
120
I presume you have dplyr and plyr loaded in the same session. dplyr is not plyr. ddply is not a ...
JSON.parse unexpected character error
...rsing an already-parsed object :)
var obj1 = JSON.parse('{"creditBalance":0,...,"starStatus":false}');
// ^ ^
// if you want to parse, the input should be a string
var obj2 = {"creditBalance":0,...,"starStatus":false};...
how do I initialize a float to its max/min value?
...west possible positive value. In other words the positive value closest to 0 that can be represented. The lowest possible value is the negative of the maximum possible value.
There is of course the std::max_element and min_element functions (defined in <algorithm>) which may be a better choic...
Returning an array using C
...t (shouldn't) do this:
char *returnArray(char array []){
char returned [10];
//methods to pull values from array, interpret them, and then create new array
return &(returned[0]); //is this correct?
}
returned is created with automatic storage duration and references to it will become inva...
Simplest code for array intersection in javascript
... Ry-♦
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answered Dec 11 '09 at 3:08
Anon.Anon.
49.5k88 gold badges...
Do try/catch blocks hurt performance when exceptions are not thrown?
...
+100
Check it.
static public void Main(string[] args)
{
Stopwatch w = new Stopwatch();
double d = 0;
w.Start();
for (in...
How to create NS_OPTIONS-style bitmask enumerations in Swift?
...
Swift 3.0
Almost identical to Swift 2.0. OptionSetType was renamed to OptionSet and enums are written lower case by convention.
struct MyOptions : OptionSet {
let rawValue: Int
static let firstOption = MyOptions(rawValue:...