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HTML5 Pre-resize images before uploading
...en you can process the images with the canvas element.
This Mozilla Hacks blog post walks you through most of the process. For reference here's the assembled source code from the blog post:
// from an input element
var filesToUpload = input.files;
var file = filesToUpload[0];
var img = document....
Difference between variable declaration syntaxes in Javascript (including global variables)?
Is there any difference between declaring a variable:
5 Answers
5
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How to randomize (or permute) a dataframe rowwise and columnwise?
...
Given the R data.frame:
> df1
a b c
1 1 1 0
2 1 0 0
3 0 1 0
4 0 0 0
Shuffle row-wise:
> df2 <- df1[sample(nrow(df1)),]
> df2
a b c
3 0 1 0
4 0 0 0
2 1 0 0
1 1 1 0
By default sample() randomly reorders the elements passed as the first argumen...
NTFS performance and large volumes of files and directories
...ry large when you have a lot of children. Note that it doesn't distinguish between a child that's a folder and a child that's a file. The only difference really is the content of that child is either the child's folder index or the child's file data. Note: I am simplifying this somewhat but this get...
Try-catch speeding up my code?
I wrote some code for testing the impact of try-catch, but seeing some surprising results.
5 Answers
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How to randomly select an item from a list?
...
Use random.choice()
import random
foo = ['a', 'b', 'c', 'd', 'e']
print(random.choice(foo))
For cryptographically secure random choices (e.g. for generating a passphrase from a wordlist) use secrets.choice()
import secrets
foo = ['battery', 'correct', 'horse', 'staple...
How to get the command line args passed to a running process on unix/linux systems?
...proc/<pid> on Linux, just have a look.
On other Unixes things might be different. The ps command will work everywhere, the /proc stuff is OS specific. For example on AIX there is no cmdline in /proc.
share
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Validating email addresses using jQuery and regex
...\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+)*|"((([ \t]*\r\n)?[ \t]+)?([\x01-\x08\x0b\x0c\x0e-\x1f\x7f\x21\x23-\x5b\x5d-\x7e\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|\\[\x01-\x09\x0b\x0c\x0d-\x7f\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))*(([ \t]*\r\n)?[ \t]+)?")@(([a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF...
MQTT物联网协议完全实践指南 · App Inventor 2 中文网
...程》
下载资源
MQTT扩展下载：
de.ullisroboterseite.ursai2pahomqtt.aix
完整示例项目：
mqtt_demo.aia
MQTT协议深度解析
1. 协议架构与通信模式
MQTT采用客户端-服务器架构，基于发布/订...
How do I test a private function or a class that has private methods, fields or inner classes?
...vate methods, fields or nested classes? Or a function that is made private by having internal linkage ( static in C/C++) or is in a private ( anonymous ) namespace?
...