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Split data frame string column into multiple columns
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Use stringr::str_split_fixed
library(stringr)
str_split_fixed(before$type, "_and_", 2)
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Rename multiple files by replacing a particular pattern in the filenames using a shell script [dupli
...a pattern. For example following command will prepend string MyVacation2011_ to all the files with jpg extension.
rename 's/^/MyVacation2011_/g' *.jpg
or
rename <pattern> <replacement> <file-list>
sha...
How do I use vimdiff to resolve a git merge conflict?
...at I want on the terminal, e.g. something along:
--- ./src/dev/arm/RealView_BASE_15560.py 2019-12-27 13:46:41.967021591 +0000
+++ ./src/dev/arm/RealView_LOCAL_15560.py 2019-12-27 13:46:41.979021479 +0000
@@ -994,7 +994,7 @@
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How do I list the symbols in a .so file
... .init
0000000000000000 DF *UND* 0000000000000000 GLIBC_2.2.5 free
0000000000000000 DF *UND* 0000000000000000 GLIBC_2.2.5 __errno_location
0000000000000000 w D *UND* 0000000000000000 _ITM_deregisterTMCloneTable
Or use readelf:
$ readelf -Ws libz.so
Sym...
How to use Elasticsearch with MongoDB?
...abase through the mongo shell and push some dummy data into it.
mongo YOUR_DATABASE_NAME
db.createCollection(YOUR_COLLECTION_NAME)
for (var i = 1; i <= 25; i++) db.YOUR_COLLECTION_NAME.insert( { x : i } )
Now to Convert the standalone MongoDB into a Replica Set.
First Shutdown the process.
m...
Counting inversions in an array
...nversion.
2a. accumulate the number of inversions to counter variable num_inversions.
2b. remove A[1] from array A and also from its corresponding position in array B
rerun from step 2 until there are no more elements in A.
Here’s an example run of this algorithm. Original array A = (6, 9, 1,...
Truncating all tables in a Postgres database
.../pgSQL can do this. Here's the script:
CREATE OR REPLACE FUNCTION truncate_tables(username IN VARCHAR) RETURNS void AS $$
DECLARE
statements CURSOR FOR
SELECT tablename FROM pg_tables
WHERE tableowner = username AND schemaname = 'public';
BEGIN
FOR stmt IN statements LOOP
...
How to spread django unit tests over multiple files?
...er valid from Django 1.6, see this post.
You can create tests folder with ___init___.py inside (so that it becomes a package). Then you add your split test .py files there and import all of them in ___init___.py.
I.e: Substitute the test.py file with a module that looks and acts like the file:
Cr...
Format floats with standard json module
...ckage). E.g., this code:
import json
from json import encoder
encoder.FLOAT_REPR = lambda o: format(o, '.2f')
print(json.dumps(23.67))
print(json.dumps([23.67, 23.97, 23.87]))
emits:
23.67
[23.67, 23.97, 23.87]
as you desire. Obviously, there should be an architected way to override FLOAT_REP...
How to convert an image to base64 encoding?
...hould be:
$path = 'myfolder/myimage.png';
$type = pathinfo($path, PATHINFO_EXTENSION);
$data = file_get_contents($path);
$base64 = 'data:image/' . $type . ';base64,' . base64_encode($data);
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