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How can I call a custom Django manage.py command directly from a test driver?
...for a Django manage.py command that does a backend operation on a database table. How would I invoke the management command directly from code?
...
How do you run a SQL Server query from PowerShell?
...dapter.Fill($dataSet) | Out-Null
$connection.Close()
$dataSet.Tables
}
I have been using this so long I don't know who wrote which parts. This was distilled from others' examples, but simplified to be clear and just what is needed without extra dependencies or features.
I use and shar...
How to insert element into arrays at specific position?
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@Artefacto "Arrays" in PHP are, in fact, ordered hash tables. PHP arrays act like arrays, but they are never really arrays; nor are they linked lists, or array lists.
– Frederik Krautwald
Aug 10 '14 at 11:31
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How can I get a list of all functions stored in the database of a particular schema in PostgreSQL?
...
After some searching, I was able to find the information_schema.routines table and the information_schema.parameters tables. Using those, one can construct a query for this purpose. LEFT JOIN, instead of JOIN, is necessary to retrieve functions without parameters.
SELECT routines.routine_name, pa...
How to scroll to specific item using jQuery?
I have a big table with vertical scroll bar.
I would like to scroll to a specific line in this table using jQuery/Javascript.
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How to remove convexity defects in a Sudoku square?
... :=
ComponentMeasurements[Image[l], "Centroid"][[1, 2]]
gridCenters =
Table[centerOfGravity[
ImageData[Dilation[Image[h], DiskMatrix[2]]]*
ImageData[Dilation[Image[v], DiskMatrix[2]]]], {h,
horizontalGridLineMasks}, {v, verticalGridLineMasks}];
The last step is to define two i...
Export from sqlite to csv using shell script
... sqlite3 command options:
sqlite3 -header -csv my_db.db "select * from my_table;" > out.csv
This makes it a one-liner.
Also, you can run a sql script file:
sqlite3 -header -csv my_db.db < my_script.sql > out.csv
Use sqlite3 -help to see the list of available options.
...
UITableView - change section header color
How can I change color of a section header in UITableView?
31 Answers
31
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How do I get the row count of a pandas DataFrame?
...use the .shape property or just len(DataFrame.index). However, there are notable performance differences ( len(DataFrame.index) is fastest).
Code to reproduce the plot:
import numpy as np
import pandas as pd
import perfplot
perfplot.save(
"out.png",
setup=lambda n: pd.DataFrame(np.arange...
Split data frame string column into multiple columns
...
5 years later adding the obligatory data.table solution
library(data.table) ## v 1.9.6+
setDT(before)[, paste0("type", 1:2) := tstrsplit(type, "_and_")]
before
# attr type type1 type2
# 1: 1 foo_and_bar foo bar
# 2: 30 foo_and_bar_2 foo ba...