大约有 44,300 项符合查询结果（耗时：0.0462秒） [XML]
Converting NSString to NSDate (and back again)
How would I convert an NSString like " 01/02/10 " (meaning 1st February 2010) into an NSDate ? And how could I turn the NSDate back into a string?
...
Printing everything except the first field with awk
...
92
Assigning $1 works but it will leave a leading space: awk '{first = $1; $1 = ""; print $0, first...
Checking the equality of two slices
...
Stephen WeinbergStephen Weinberg
41.2k1212 gold badges112112 silver badges103103 bronze badges
...
How to get row from R data.frame
...is, for example:
#Add your data
x <- structure(list(A = c(5, 3.5, 3.25, 4.25, 1.5 ),
B = c(4.25, 4, 4, 4.5, 4.5 ),
C = c(4.5, 2.5, 4, 2.25, 3 )
),
.Names = c("A", "B", "C"),
class = "da...
What does .SD stand for in data.table in R
...
206
.SD stands for something like "Subset of Data.table". There's no significance to the initial "...
Script to get the HTTP status code of a list of urls?
...curl -o /dev/null --silent --head --write-out '%{http_code}\n' <url>
200
-o /dev/null throws away the usual output
--silent throws away the progress meter
--head makes a HEAD HTTP request, instead of GET
--write-out '%{http_code}\n' prints the required status code
To wrap this up in a com...
Generator Expressions vs. List Comprehension
...
294
John's answer is good (that list comprehensions are better when you want to iterate over somet...
What is the difference between the Facade and Adapter Pattern?
...
142
The Facade Pattern wiki page has a brief note about this.
"An Adapter is used when the wra...
How to trim leading and trailing white spaces of a string?
...
269
For example,
package main
import (
"fmt"
"strings"
)
func main() {
s := "\t Hel...
How to print the full traceback without halting the program?
...in some corner cases, you will not obtain what you would expect. In Python 2.x:
import traceback
try:
raise TypeError("Oups!")
except Exception, err:
try:
raise TypeError("Again !?!")
except:
pass
traceback.print_exc()
...will display the traceback of the last ex...