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Java 8: performance of Streams vs Collections
I'm new to Java 8. I still don't know the API in depth, but I've made a small informal benchmark to compare the performance of the new Streams API vs the good old Collections.
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Perl build, unit testing, code coverage: A complete working example
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It took me a while and it also took me taking small snippets from a number of different sources and melting them together, but I think I have a small working example that sufficiently demonstrates to a Perl newbie the Perl build process including unit testing and code cove...
MySQL - length() vs char_length()
...() returns the length of the string measured in characters.
This is especially relevant for Unicode, in which most characters are encoded in two bytes. Or UTF-8, where the number of bytes varies. For example:
select length(_utf8 '€'), char_length(_utf8 '€')
--> 3, 1
As you can see the E...
.rar, .zip files MIME Type
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actually there's another MIME TYPE for zip, and that's: application/x-zip-compressed
– Kiyarash
Oct 6 '14 at 19:21
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e.printStackTrace equivalent in python
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import traceback
traceback.print_exc()
When doing this inside an except ...: block it will automatically use the current exception. See http://docs.python.org/library/traceback.html for more information.
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How to check if a table contains an element in Lua?
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Perhaps also function keysOfSet(set) local ret={} for k,_ in pairs(set) do ret[#ret+1]=k end return ret end
– Jesse Chisholm
Apr 27 '18 at 21:40
add a comme...
How often does python flush to a file?
...t size.
A negative buffering means to use the system default, which is usually line buffered for tty devices and fully buffered for other files.
If omitted, the system default is used.
code:
bufsize = 0
f = open('file.txt', 'w', buffering=bufsize)
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Backup/Restore a dockerized PostgreSQL database
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Backup your databases
docker exec -t your-db-container pg_dumpall -c -U postgres > dump_`date +%d-%m-%Y"_"%H_%M_%S`.sql
Restore your databases
cat your_dump.sql | docker exec -i your-db-container psql -U postgres
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How do I globally configure RSpec to keep the '--color' and '--format specdoc' options turned on
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One can also use a spec_helper.rb file in all projects. The file should include the following:
RSpec.configure do |config|
# Use color in STDOUT
config.color = true
# Use color not only in STDOUT but also in pagers and files
config.tty = true
# Use the s...
Django admin: how to sort by one of the custom list_display fields that has no database field
How could I sort Customers, depending on number_of_orders they have?
3 Answers
3
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