emerge | Simple package installer

Hi I am looking for help to study pre-existing models that are IoT based but has applications such as radio frequency identification, emergency related, and some form of access control, a paper in that area is ideal. Thanks in advance!

I have a function that when someone enters a number in the textbox and when I click the search button, the function returns an image!my problem is when for the first time I click the search button, everything is ok,but when I click the button twice, again the same picture emerge in my form.How can I run just once for every input?Here is my code

Suppose we have a SQL table with entries for different dates such as

main_table:

I would like to retrieve the entries between '30-05-2021' and '07-06-2021'. But the resulting output_table table should be in a business days format such that

output_table:

If I query the table with a simple SELECT * WHERE date>='30-05-2021' AND date <= '07-06-2021' query the following problems would emerge:

• The date '03-06-2021' (a weekday) would be missing.
• There would be no entry for '31-05-2021' (not in main_table).
• The date '05-06-2021' would be retrieved which is, however, no business day (Saturday).

Essentially my idea was to create a business day table (date_table) and subsequently use a left join of main_table on date_table:

I'd like to create a regex that would be able to grab everything up to and after DESCRIPTION, until the next TITLE: is found.

I am writing a small TCP sockets "library", and I ran into much trouble.

When something happens to the socket that causes it to be instantly closed and freed (regardless of background lingering, talking about user space here), which is only done within a locked mutex since the application I'm writing is multi-threaded, I need a way to tell all the other (potentially) waiting threads (on the same mutex) that want to do something with the socket: "I'm terribly sorry, but the socket has been destroyed and you cannot access it" so that they don't cause any segmentation fault or such.

The idea I had was: the mutex was part of the socket (socket = a structure that contains multiple things, including a mutex and a file descriptor) so I couldn't quite free the socket if other threads were waiting for it (undefined behavior), so the possible solution is to allocate the mutex, free the socket but not the mutex, set some flag (in the allocated memory) saying that the socket has been closed, and a counter so that the last thread waking up and getting notified that it cannot use the socket unlocks and destroys the mutex and frees the memory allocated. The mutex can still be accessed without segfault if we just store its pointer before acquiring the mutex (and the pointer won't ever change).

This solution has a fundamental problem though - what if between unlocking the mutex and freeing it by the last holder, the thread gets preempted and another one locks the mutex again (since you NEED to check socket-related stuff after you acquire the lock, so no way of knowing it got destroyed, unless you maybe use an atomic variable but then again, checking the atomic variable and locking the mutex as a whole are not an atomic operation). Or if you try to access the mutex on the already-freed socket. Undefined behavior emerges.

Any ideas how to solve this problem? I.e. how to destroy a socket so that other threads know about it to quit safely, and there are no race conditions? By quitting I mean aborting the socket function they were in, not cancelling or stopping the threads themselves.

I'm trying to pass some json data from my database to front-end so that I can manipulate those with javascript! I started by creating some temporary json data in my home.html.erb as follows:

I am creating a custom activity indicator view and I am having difficulty implementing the animation that I want for my indicator. The first part of the animation has the dots emerge. When the dots have emerged the following set of images are looped over to indicate that something is loading. Finally once a condition is met it will trigger the image view to animate the last set of images which make the dots disappear. In total there are 150 images.

I have an html form for registering for a club. I then have a php script that I want to have called that will send an email to me with the registration info. What I need to have happen is have the PHP script called once I get a successful payment through paypal. Under sandbox I am successfully hitting the 'onApprove' callback. I just wonder how I call the PHP file and post the data from the form. Any help would be appreciated. Or if there's a better way to do it, please let me know.

HTML:

Relatively new to Dash, and this is a problem that has been vexing me for months now. I am making a multi-page app that shows some basic data trends using cards, and graphs embedded within cardbody. 30% of the time, the app works well without any errors and the other 70% it throws either one of the following:

1. ImportError: cannot import name 'ValidatorCache' from partially initialized module 'plotly.validator_cache' (most likely due to a circular import) OR
2. ImportError: cannot import name 'Layout' from partially initialized module 'plotly.graph_objects' (most likely due to a circular import)

Both these appear quite randomly and I usually refresh the app to make them go away. But obviously I am doing something wrong. I have a set of dropdowns that trigger callbacks on graphs. I have been wracking my head about this. Any help/leads would be appreciated. The only pattern I see in the errors is they seem to emerge when the plotly express graphs are being called in the callbacks.

What am I doing wrong? I have searched all over online for help but nothing yet.

Sharing with some relevant snippets of code (this may be too long and many parts not important to the question, but to give you a general idea of what I have been working towards)