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define() vs. const
... of PHP 5.3 there are two ways to define constants: Either using the const keyword or using the define() function:
const FOO = 'BAR';
define('FOO', 'BAR');
The fundamental difference between those two ways is that const defines constants at compile time, whereas define defines them at run time. T...
Accessing elements of Python dictionary by index
Consider a dict like
10 Answers
10
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Automatic exit from bash shell script on error [duplicate]
...o want to employ all or some of the the -e -u -x and -o pipefail options like so:
set -euxo pipefail
-e exits on error, -u errors on undefined variables, and -o (for option) pipefail exits on command pipe failures. Some gotchas and workarounds are documented well here.
(*) Note:
The shell do...
Get PostGIS version
...
Since some of the functions depend on other libraries like GEOS and proj4 you might want to get their versions too. Then use:
SELECT PostGIS_full_version();
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Pandas every nth row
Dataframe.resample() works only with timeseries data. I cannot find a way of getting every nth row from non-timeseries data. What is the best method?
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Find all tables containing column with specified name - MS SQL Server
...N sys.tables t ON c.object_id = t.object_id
WHERE c.name LIKE '%MyName%'
ORDER BY TableName
,ColumnName;
Search Tables & Views:
SELECT COLUMN_NAME AS 'ColumnName'
,TABLE_NAME AS 'TableName'
FROM INFORMATION_SCHEMA.COLUMNS
WHERE COL...
Selecting all text in HTML text input when clicked
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You can use this javascript snippet:
<input onClick="this.select();" value="Sample Text" />
But apparently it doesn't work on mobile Safari. In those cases you can use:
<input onClick="this.setSelectionRange(0, this.value.length)" value="Sample Text" />
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How to create empty text file from a batch file?
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TheSmurfTheSmurf
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Convert hex color value ( #ffffff ) to integer value
... values from a server (in this form, #xxxxxx , example #000000 for black)
9 Answers
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Aggregate / summarize multiple variables per group (e.g. sum, mean)
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Where is this year() function from?
You could also use the reshape2 package for this task:
require(reshape2)
df_melt <- melt(df1, id = c("date", "year", "month"))
dcast(df_melt, year + month ~ variable, sum)
# year month x1 x2
1 2000 1 -80.83405 -224.9540159
2 2000 ...