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Assignment inside lambda expression in Python
...asons. For example, we will be able to write the following:
import sys
say_hello = lambda: (
message := "Hello world",
sys.stdout.write(message + "\n")
)[-1]
say_hello()
In Python 2, it was possible to perform local assignments as a side effect of list comprehensions.
import sys
say_hell...
Local variables in nested functions
...s to the function, with the code using an index to reference each cell. pet_function thus has one free variable (cage) which is then referenced via a closure cell, index 0. The closure itself points to the local variable cage in the get_petters function.
When you actually call the function, that cl...
Thread Safety in Python's dictionary
...mic operations, there are corner cases where they aren’t atomic (e.g. if __hash__ or __eq__ are implemented as Python methods) and their atomicity should not be relied upon. Neither should you rely on atomic variable assignment (since this in turn depends on dictionaries).
Use the Queue module's Q...
Running python script inside ipython
...
from within the directory of "my_script.py" you can simply do:
%run ./my_script.py
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Why rename synthesized properties in iOS with leading underscores? [duplicate]
...ariables had to be instantiated explicitly:
@interface Foo : Bar {
Baz *_qux;
}
@property (retain) Baz *qux;
@end
@implementation Foo
@synthesize qux = _qux;
- (void)dealloc {
[_qux release];
[super dealloc];
}
@end
People would prefix their instance variables to differentiate them from...
What it the significance of the Javascript constructor property?
...y to find attr among x's attributes. If it cant find it, it will look in x.__proto__. If it's not there either, it will look in x.__proto__.__proto__ and so on as long as __proto__ is defined.
So what is __proto__and what has it got to do with prototype? Shortly put, prototype is for "types" while ...
How to paste over without overwriting register
...o hide this function (yet)
function! RestoreRegister()
let @" = s:restore_reg
return ''
endfunction
function! s:Repl()
let s:restore_reg = @"
return "p@=RestoreRegister()\<cr>"
endfunction
" NB: this supports "rp that replaces the selection by the contents of @r
vnoremap <sile...
Check if a Windows service exists and delete in PowerShell
...ee Remove-Service doc)
For example:
$service = Get-WmiObject -Class Win32_Service -Filter "Name='servicename'"
$service.delete()
Or with the sc.exe tool:
sc.exe delete ServiceName
Finally, if you do have access to PowerShell 6.0:
Remove-Service -Name ServiceName
...
How to output a multiline string in Bash?
...ters. This seems reasonably portable to me (I ran it on MacOS and Ubuntu)
__usage="
Usage: $(basename $0) [OPTIONS]
Options:
-l, --level <n> Something something something level
-n, --nnnnn <levels> Something something something n
-h, --help ...
How to send an email from JavaScript
...= require('node-mandrill')('<your API Key>');
function sendEmail ( _name, _email, _subject, _message) {
mandrill('/messages/send', {
message: {
to: [{email: _email , name: _name}],
from_email: 'noreply@yourdomain.com',
subject: _subject,
...