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const char* concatenation
I need to concatenate two const chars like these:
12 Answers
12
...
Fast check for NaN in NumPy
...t np.isnan(np.sum(x))
10000 loops, best of 3: 95.9 us per loop
In [43]: x[50000] = np.nan
In [44]: %timeit np.isnan(np.min(x))
1000 loops, best of 3: 239 us per loop
In [45]: %timeit np.isnan(np.sum(x))
10000 loops, best of 3: 95.8 us per loop
In [46]: x[0] = np.nan
In [47]: %timeit np.isnan(np...
How to see indexes for a database or table in MySQL?
...ed database.
SELECT TABLE_NAME,
COUNT(1) index_count,
GROUP_CONCAT(DISTINCT(index_name) SEPARATOR ',\n ') indexes
FROM INFORMATION_SCHEMA.STATISTICS
WHERE TABLE_SCHEMA = 'mydb'
AND INDEX_NAME != 'primary'
GROUP BY TABLE_NAME
ORDER BY COUNT(1) DESC;
...
Does JavaScript have a built in stringbuilder class?
...et Explorer make sure you chose an implementation, which uses array joins. Concatenating strings with the + or += operator are extremely slow on IE. This is especially true for IE6. On modern browsers += is usually just as fast as array joins.
When I have to do lots of string concatenations I usua...
Compare two DataFrames and output their differences side-by-side
....
Using the example data from the original question
The first step is to concatenate the DataFrames horizontally with the concat function and distinguish each frame with the keys parameter:
df_all = pd.concat([df.set_index('id'), df2.set_index('id')],
axis='columns', keys=['Fi...
SASS - use variables across multiple files
...S Task
var gulp = require('gulp');
var sass = require('gulp-sass');
//var concat = require('gulp-concat');
var uglifycss = require('gulp-uglifycss');
var sourcemaps = require('gulp-sourcemaps');
gulp.task('styles', function(){
return gulp
.src('sass/**/*.scss')
.pipe(so...
Prepend text to beginning of string
...
Since we want to test prepend, and not just concatenate, I've updated the tests: jsperf.com/prepend-text-to-string/5
– metalim
Apr 22 '19 at 11:32
...
How to copy a row and insert in same table with a autoincrement field in MySQL?
...xt)
SQL SECURITY INVOKER
BEGIN
SELECT IF(TRIM(_omitColumns) <> '', CONCAT('id', ',', TRIM(_omitColumns)), 'id') INTO @omitColumns;
SELECT GROUP_CONCAT(COLUMN_NAME) FROM information_schema.columns
WHERE table_schema = _schemaName AND table_name = _tableName AND FIND_IN_SET(COLUMN_NAME,@...
SQL order string as number
... leading zeros to make all integer strings having equal length.
ORDER BY CONCAT( REPEAT( "0", 18 - LENGTH( stringfield ) ) , stringfield )
or order by part of a field something like 'tensymbols13', 'tensymbols1222' etc.
ORDER BY CONCAT( REPEAT( "0", 18 - LENGTH( LEFT( stringfield , 10 ) ) ) ...
Get table column names in MySQL?
...
How about this:
SELECT @cCommand := GROUP_CONCAT( COLUMN_NAME ORDER BY column_name SEPARATOR ',\n')
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'my_database' AND TABLE_NAME = 'my_table';
SET @cCommand = CONCAT( 'SELECT ', @cCommand, ' from my_database.my_t...